Best Time to Water Grass: Hours, Minutes and Inches per Week

Key takeaways

• Purdue Extension names 4 to 8 a.m. as the ideal watering window and 8 a.m. to noon as second best (Purdue AY-7); NC State says watering between 2 and 8 a.m. cuts some lawn diseases (NC State AG-367).
• Evening watering is the disease risk: some turf diseases can develop in as little as 2 hours under a film of water, so K-State says to stop at least 30 minutes before sundown (K-State MF2059).
• Most actively growing lawns need about 1 inch of water a week from rain plus irrigation, wetting the soil 4 to 6 inches deep (NC State AG-431; AG-367). In hot, dry climates that rises: UC’s July schedule for cool-season grass in the Southern California deserts works out to about 2.5 inches a week (UC IPM Zone 11).
• Run time depends on the nozzle: 1 inch takes about 38 minutes from a Rain Bird 15 Series spray nozzle at 1.58 in/hr (Rain Bird catalog) but 150 minutes from a Hunter MP Rotator at 0.4 in/hr (Hunter).
• Midday watering wastes water but does not burn turf (Purdue AY-7). Many cities ban it anyway: Dallas prohibits sprinklers from 10 a.m. to 6 p.m. on any day (Dallas Water Utilities).

What is the best time of day to water grass?

Early morning is the best time to water grass, ideally 4 to 8 a.m. Purdue Extension AY-7 picks that window because water pressure is usually highest, wind barely distorts the spray pattern and evaporation loss is negligible. The lawn then dries as the sun comes up, which shortens the time leaves stay wet. Late morning, 8 a.m. to noon, is Purdue’s second choice.

Key number	Value	Source
Ideal watering window	4 to 8 a.m.	Purdue AY-7
Second-best window	8 a.m. to noon	Purdue AY-7
Disease-reducing window, tall fescue	2 to 8 a.m.	NC State AG-367, 2021
Leaf wetness that can start some diseases	As little as 2 hours	K-State MF2059, 2018
Latest evening shut-off	30 minutes before sundown	K-State MF2059, 2018
Weekly water, actively growing lawn	About 1 inch, rain included	NC State AG-431, 2021
Depth to wet the soil	4 to 6 inches	NC State AG-367
Outdoor water lost to wind, evaporation and runoff	As much as 50 percent	EPA WaterSense, 2026

Extension services agree on the morning but not on the exact hours: the 4 published windows that give clock times start anywhere from 9 p.m. to 4 a.m. The next table sets them beside the hours that 8 U.S. water utilities and agencies allow, so you can see where the advice overlaps with rules you may have to follow.

Source	Type	Hours named for sprinkler watering	Reason given
Purdue Extension AY-7	Extension (Indiana)	4 to 8 a.m. ideal; 8 a.m. to noon second	High water pressure, little wind, negligible evaporation
NC State Extension AG-367	Extension (North Carolina)	2 to 8 a.m.	Decreases certain diseases, including brown patch
Nebraska Extension, UNL Water	Extension (Nebraska)	4 to 10 a.m.	Blades dry, less evaporation and wind
Colorado State University Extension	Extension (Colorado)	9 p.m. to 9 a.m.	Less evaporation; less wind drift early
UF/IFAS Extension LH025	Extension (Florida)	Early morning	Daytime watering loses water; late watering stretches the dew period
K-State Research and Extension MF2059	Extension (Kansas)	Morning; stop 30 minutes before sundown	Less evaporation and wind; disease in as little as 2 hours
EPA WaterSense	Federal agency	Early morning and evening after sundown	Heat-of-day evaporation
Georgia EPD	State rule	4 p.m. to 10 a.m.	Water Stewardship Act schedule

• Extension windows that include the hour (of 4)
• Utility or state rules that allow sprinklers (of 8)

Source: Green Industry Report count from Purdue AY-7, NC State AG-367, Nebraska Extension, CSU Extension and the published rules of Dallas, LADWP, SNWA, SFWMD, Georgia EPD, Denver Water, Austin Water and SAWS, checked Oct. 19, 2026 Each point counts the hour that starts at the label. SNWA hours are its May 1 to Aug. 31 rule; SAWS hours are Stage 3.

Show the numbers

	Extension windows that include the hour (of 4)	Utility or state rules that allow sprinklers (of 8)
12 a.m.	1	7
1 a.m.	1	7
2 a.m.	2	7
3 a.m.	2	7
4 a.m.	4	7
5 a.m.	4	8
6 a.m.	4	8
7 a.m.	4	8
8 a.m.	2	8
9 a.m.	1	7
10 a.m.	0	1
11 a.m.	0	0
12 p.m.	0	0
1 p.m.	0	0
2 p.m.	0	0
3 p.m.	0	0
4 p.m.	0	3
5 p.m.	0	3
6 p.m.	0	5
7 p.m.	0	7
8 p.m.	0	7
9 p.m.	1	8
10 p.m.	1	8
11 p.m.	1	8

Hours	Extension windows that include these hours (of 4)	Watering rules that allow sprinklers (of 8)
midnight to 2 a.m.	1	7
2 a.m. to 4 a.m.	2	7
4 a.m. to 5 a.m.	4	7
5 a.m. to 8 a.m.	4	8
8 a.m. to 9 a.m.	2	8
9 a.m. to 10 a.m.	1	7
10 a.m. to 11 a.m.	0	1
11 a.m. to 4 p.m.	0	0
4 p.m. to 6 p.m.	0	3
6 p.m. to 7 p.m.	0	5
7 p.m. to 9 p.m.	0	7
9 p.m. to midnight	1	8

The overlap is 5 to 8 a.m.: all 4 extension windows include those hours, and all 8 rules allow sprinklers then. From 11 a.m. to 4 p.m. none of the 8 rules allows sprinkler watering, which matches EPA WaterSense advice to avoid the middle of the day, when the hot sun evaporates much of the water.

Why is evening watering riskier than morning watering?

Evening watering leaves grass wet through the night, and wet leaves are how fungal diseases start. K-State Research and Extension says some turf diseases can develop in as little as 2 hours when a film of water stays on the grass, so if evening is your only option, shut the water off at least 30 minutes before sundown. Night watering should be timed to finish after sunup.

The same leaf-wetness clock explains when extension services say to skip mowing wet grass and when a dew-wet cut is harmless.

Humidity and night temperature decide how big the risk is. NC State Extension says brown patch on tall fescue turns severe in overcast, wet weather when evening air stays above 68°F and days reach the mid to upper 80s, and gray leaf spot develops when nights stay above 70°F. In dry Colorado, Denver Water says watering at night is fine because low humidity keeps mildew from taking hold.

Is it bad to water grass in the middle of the day?

Midday watering wastes water but does not burn grass. Purdue Extension says midday watering is not very effective because a large amount evaporates, yet it does not cause the turf to burn, and K-State calls mid-afternoon the least efficient time while noting it is not harmful to the grass. If a lawn is severely wilted, K-State says to water immediately, whatever the hour.

The leaf-burn idea comes from water droplets acting as lenses. A 2010 study in New Phytologist (Egri and colleagues) found that sunlit drops on smooth, hairless maple and ginkgo leaves did not cause burn damage; only drops held above the leaf by water-repellent hairs, as on floating fern, focused enough light. Nebraska Extension even recommends a 5 to 10 minute afternoon run per zone on days above 90°F to cool turf (UNL Water).

How much water does grass need per week?

Most actively growing lawns need about 1 inch of water a week, counting rain, applied so the soil is wet 4 to 6 inches deep. That is the figure in NC State Extension calendars for bermudagrass, centipedegrass, St. Augustinegrass and tall fescue. Zoysiagrass gets by on 0.5 to 1 inch, sandy soils need about 1/2 inch every third day, and hot, dry climates need more.

Grass or situation	Water per week	How to apply it	Source
Tall fescue (North Carolina)	About 1 inch	Not all at once; wet soil 4 to 6 inches deep	NC State AG-367
Tall fescue in dry summer weather (Kansas)	1 to 1.5 inches	Once or twice a week; morning is best	K-State MF736, 2015
Bermudagrass	About 1 inch	Water at bluish-gray color or folded leaves	NC State AG-431
Zoysiagrass	0.5 to 1 inch	Wet soil 4 to 6 inches deep	NC State AG-432, 2025
Centipedegrass	About 1 inch	Rain plus irrigation	NC State AG-381
St. Augustinegrass	About 1 inch	Rain plus irrigation	NC State AG-540
St. Augustinegrass and other Florida lawns	1/2 to 3/4 inch per watering	Only when leaves fold or turn blue-gray	UF/IFAS LH025
Any grass on sandy soil	About 1/2 inch every third day	Shorter, more frequent	NC State AG-381
Indiana lawns	1 to 1.5 inches	One soaking, or two 3 to 4 days apart	Purdue AY-7
Georgia established lawns	About 1 inch	For example, two 1/2-inch waterings 3 to 4 days apart	UGA Extension
Minnesota lawns	As little as 1/2 inch	Once a week or less, wetting 6 inches	University of Minnesota Extension
Dormant lawn in a long drought	1 to 1.5 inches every 4 to 6 weeks	Keeps crowns and roots alive	Purdue AY-7

Grass type sets how often, too. K-State MF2059 ranks irrigation frequency from least to most: buffalograss, bermudagrass, tall fescue, zoysiagrass, Kentucky bluegrass and perennial ryegrass. Our profiles of tall fescue, zoysia grass and St. Augustine grass carry the per-grass watering detail.

Why 1 inch a week is too little in hot, dry climates

The 1-inch rule is a humid-climate average; water need follows evaporation. The UC Guide to Healthy Lawns publishes weekly run times by California climate zone for a sprinkler applying 1 inch per hour, so each 60 minutes equals 1 inch. In July, cool-season grass needs 71 minutes (1.18 inches) on the Southern California coast and 151 minutes (2.52 inches) in the Southern California deserts.

• SoCal coast, cool-season
• SoCal inland valleys, cool-season
• SoCal deserts, cool-season
• SoCal inland valleys, warm-season

Source: UC Statewide IPM Program, UC Guide to Healthy Lawns, Zones 9, 10 and 11 (minutes per week for a 1 inch per hour sprinkler, divided by 60) Inches are Green Industry Report arithmetic from UC's published minutes.

Show the numbers

	SoCal coast, cool-season	SoCal inland valleys, cool-season	SoCal deserts, cool-season	SoCal inland valleys, warm-season
Jan	0.48	0.47	0.53	0.35
Feb	0.63	0.63	0.77	0.47
Mar	0.70	0.88	1.22	0.67
Apr	0.83	1.07	1.67	0.80
May	0.98	1.33	2.12	1
Jun	1.05	1.60	2.42	1.20
Jul	1.18	1.83	2.52	1.38
Aug	1.05	1.72	2.18	1.28
Sep	0.92	1.37	1.80	1.03
Oct	0.77	0.98	1.22	0.73
Nov	0.57	0.60	0.70	0.45
Dec	0.42	0.63	0.43	0.35

Month	SoCal coast, cool-season	SoCal inland valleys, cool-season	San Joaquin Valley, cool-season	SoCal deserts, cool-season	SoCal inland valleys, warm-season	SoCal deserts, warm-season
January	0.48 (29 min)	0.47 (28 min)	0.22 (13 min)	0.53 (32 min)	0.35 (21 min)	0.45 (27 min)
February	0.63 (38 min)	0.63 (38 min)	0.42 (25 min)	0.77 (46 min)	0.47 (28 min)	0.63 (38 min)
March	0.70 (42 min)	0.88 (53 min)	0.77 (46 min)	1.22 (73 min)	0.67 (40 min)	1.02 (61 min)
April	0.83 (50 min)	1.07 (64 min)	1.12 (67 min)	1.67 (100 min)	0.80 (48 min)	1.38 (83 min)
May	0.98 (59 min)	1.33 (80 min)	1.47 (88 min)	2.12 (127 min)	1.00 (60 min)	1.77 (106 min)
June	1.05 (63 min)	1.60 (96 min)	1.82 (109 min)	2.42 (145 min)	1.20 (72 min)	2.02 (121 min)
July	1.18 (71 min)	1.83 (110 min)	1.88 (113 min)	2.52 (151 min)	1.38 (83 min)	2.10 (126 min)
August	1.05 (63 min)	1.72 (103 min)	1.62 (97 min)	2.18 (131 min)	1.28 (77 min)	1.82 (109 min)
September	0.92 (55 min)	1.37 (82 min)	1.27 (76 min)	1.80 (108 min)	1.03 (62 min)	1.50 (90 min)
October	0.77 (46 min)	0.98 (59 min)	0.77 (46 min)	1.22 (73 min)	0.73 (44 min)	1.02 (61 min)
November	0.57 (34 min)	0.60 (36 min)	0.35 (21 min)	0.70 (42 min)	0.45 (27 min)	0.58 (35 min)
December	0.42 (25 min)	0.63 (38 min)	0.13 (8 min)	0.43 (26 min)	0.35 (21 min)	0.37 (22 min)

Warm-season grass in the same zone needs about a quarter less: in UC’s Southern California inland valleys table, July is 83 minutes for warm-season grass against 110 for cool-season, about 25 percent less. The same tables show why a timer set in spring overwaters in fall. Zone 10 cool-season need falls from 110 minutes a week in July to 59 in October.

How long should you water your lawn?

Water long enough to apply the target depth, usually 1/2 to 1 inch per session, and that time depends entirely on your sprinkler’s output in inches per hour. Divide the inches you want by the output and multiply by 60. A spray nozzle at 1.58 in/hr needs about 19 minutes for 1/2 inch; a rotary nozzle at 0.4 in/hr needs 75 minutes.

Sprinkler and nozzle	Published output	Minutes for 1/2 inch	Minutes for 1 inch	Source
Rain Bird 15 Series MPR spray nozzle, 30 psi, square spacing (15 ft radius)	1.58 in/hr	19 min	38 min	Rain Bird 2019 spray nozzle catalog
Rain Bird 15 Series MPR spray nozzle, 30 psi, triangular spacing (15 ft radius)	1.83 in/hr	16 min	33 min	Rain Bird 2019 spray nozzle catalog
Hunter MP800 rotary nozzle (6 to 24 ft radius)	0.8 in/hr	38 min	75 min	Hunter MP Rotator precipitation rates
Rain Bird R-VAN14 rotary nozzle, 45 psi, square spacing (14 ft radius)	0.62 in/hr	48 min	97 min	Rain Bird 2019 spray nozzle catalog
Hunter MP Rotator standard nozzle (up to 35 ft radius)	0.4 in/hr	75 min	150 min	Hunter MP Rotator precipitation rates
Your own system, measured with catch cups (UF example: 1/4 inch in 15 minutes)	1 in/hr	30 min	60 min	UF/IFAS LH025 method

Hose-end sprinklers are the slowest. Purdue Extension says most should stay in one spot for 2 to 3 hours to wet the root zone, while in-ground spray heads deliver a large volume in 10 to 15 minutes and single-stream rotors need 30 to 40 minutes. Those Purdue figures are rough guides; a catch-cup test replaces them with your own number.

How to measure your sprinkler output with catch cups

A catch-cup test turns guesswork into a run time in about 20 minutes. UF/IFAS Extension uses straight-sided cans set in a line from the sprinkler to the edge of its pattern and a 15-minute run; NDSU Extension spaces cups 5 to 10 feet apart. Multiply the average depth caught by 4 to get inches per hour.

1. Set out 5 to 10 straight-sided cans or cups (tuna cans work) in a line or grid, 5 to 10 feet apart, from the head to the edge of the spray (NDSU; UF/IFAS).
2. Run the zone, or the hose-end sprinkler, for exactly 15 minutes (UF/IFAS LH025).
3. Measure the water in each can with a ruler. UF/IFAS looks for about equal amounts in every can; a can that stays nearly dry marks a clogged, tilted or blocked head to fix before setting times.
4. Average the depths and multiply by 4 for inches per hour. Example: an average of 1/4 inch in 15 minutes is 1 in/hr.
5. Divide your target by that rate and multiply by 60: 1/2 inch ÷ 1 in/hr × 60 = 30 minutes. UF/IFAS gives the same answer: 30 to 45 minutes for 1/2 to 3/4 inch.
6. Watch the first full run. If water pools or runs off before the time is up, the sprinkler is applying water faster than the soil absorbs it (K-State MF2059); split the run into cycles as in the clay and slope section.

Once the run times are set, the controller does the scheduling. A WaterSense labeled controller that adjusts to weather can cut an average home’s irrigation water use by up to 30 percent (EPA WaterSense). Our guide to sprinkler system installation cost prices controllers and zones, and broken heads found in the cup test are priced in our sprinkler repair cost guide.

How often should you water your lawn?

Water an established lawn once or twice a week in most climates, only when it shows stress, and deeply each time. Purdue Extension prefers one thorough soaking or two equal waterings 3 to 4 days apart over light daily watering, which it says promotes shallow roots and crabgrass. Sandy soil and summer heat shorten the interval.

Season	Pensacola (days between waterings)	Gainesville	Miami
Winter	8 to 28	7 to 23	3 to 10
Spring	3 to 11	3 to 9	2 to 7
Summer	1 to 5	1 to 5	1 to 4
Fall	2 to 9	2 to 8	2 to 6

The seasonal swing is the point: in Pensacola the gap runs from 1 to 5 days in summer to 8 to 28 days in winter, so a timer left on its summer setting overwaters for months. UF/IFAS says to reset controllers each season and, after 1/2 to 3/4 inch of rain, to wait until the grass shows stress again. K-State adds a firm line: avoid watering every day or even every other day, except on a newly seeded lawn.

How do you water clay soil or a slope without runoff?

Use cycle and soak: split each zone’s run into 2 or 3 short cycles with a rest between them so water soaks in instead of running off. Clay absorbs water slowly, and a spray head can apply it 8 times faster than compacted clay takes it in. Colorado State Extension suggests about 1/4 inch per cycle, roughly 8 to 10 minutes on pop-up sprays.

Soil under healthy sod	Water absorbed in an hour without runoff	Versus a spray nozzle at 1.58 in/hr
Coarse sandy loam	1.3 inch	Spray is 1.2 times faster
Sandy loam	1.0 inch	1.6 times faster
Silt loam	0.6 inch	2.6 times faster
Silty clay loam	0.5 inch	3.2 times faster
Compacted clay	0.2 inch	7.9 times faster

Slope cuts the safe rate further. K-State’s MF2059 reduces the watering rate by 0 to 10 percent on 0 to 5 percent slopes, 20 to 45 percent on 10 to 15 percent slopes and 60 percent or more above 20 percent. Denver Water rests flat lawns 30 minutes between cycles and slopes 60 minutes.

Step	Input	Result
Target per watering day	1/2 to 3/4 inch (CSU)	Plan 3 cycles of 1/4 inch = 3/4 inch
Nozzle output	Rain Bird 15 Series spray, 1.58 in/hr	1/4 inch ÷ 1.58 × 60 = 9.5 minutes per cycle
Soak time between cycles	Flat lawn 30 minutes; slope 60 minutes (Denver Water)	Slope: 3 runs of 9.5 minutes + 2 rests of 60 minutes = 148.5 minutes
Slope of 10 to 15 percent	Cut the rate 20 to 45 percent (K-State)	Shorten each cycle to about 5 to 8 minutes and add a fourth cycle
Start time	Finish by 8 a.m. (Purdue)	Start the first cycle at about 5:30 a.m.

1. Run the zone until water starts to pool or run off, and note the minutes. That is your maximum cycle length (K-State MF2059; Purdue AY-7).
2. Divide the zone’s total run time by that cycle length and round up to get the number of cycles, usually 2 or 3.
3. Set the controller’s cycle-and-soak feature, or extra start times, with a 30-minute rest on flat ground and 60 minutes on slopes (Denver Water).
4. On compacted clay at 0.2 in/hr, a 1/4-inch cycle needs about 75 minutes to soak in, so rest longer or core-aerate to raise intake.

Core aeration is the long-term fix for compacted clay: K-State recommends aerating clay soils 2 to 3 inches deep once or twice a year to increase water penetration. Our guide to when to aerate your lawn sets the month for each grass.

What watering hours do cities enforce?

Most large Western and Southern utilities ban sprinkler watering in the hottest hours, so the legal window often decides the best time for you. As of October 2026, the 8 rules below all allow sprinklers from 5 to 9 a.m., and none allows them from 11 a.m. to 4 p.m. Several also cap watering days, and Los Angeles caps minutes per station.

Utility or agency	Sprinkler hours allowed	Days and other limits	Source, as of October 2026
Dallas Water Utilities	Before 10 a.m. or after 6 p.m., any day of the year	Up to 2 assigned days a week; no watering Monday, Tuesday or Friday; hand watering, drip and soaker hoses any time	Save Dallas Water FAQ
LADWP, Los Angeles	Before 9 a.m. or after 4 p.m.	3 assigned days; 8 minutes per station per day for standard sprays, or two 15-minute cycles for water-conserving nozzles; none during rain and for 48 hours after; fines $100 to $600	LADWP watering days fact sheet
SNWA, Las Vegas Valley	May 1 to Aug. 31: not from 11 a.m. to 7 p.m.	3 assigned days March to April and September to October; 1 day November to February; never Sunday	SNWA watering clock page
South Florida Water Management District	Not from 10 a.m. to 4 p.m., year-round	2 or 3 days a week depending on area (Chapter 40E-24, F.A.C.)	SFWMD landscape irrigation
Georgia EPD, statewide	4 p.m. to 10 a.m.	Statewide Drought Response Level 1 declared April 27, 2026 and kept Aug. 14, 2026; the hours are unchanged at Level 1	Georgia EPD drought management
Denver Water	Not from 10 a.m. to 6 p.m. (summer rules, May 1 to Oct. 1)	2026 Stage 1 drought: 2 assigned days a week; from Oct. 1, 2026 all lawn watering and spray irrigation prohibited until further notice	Denver Water summer rules; Denver Water drought notice
Austin Water	Midnight to 10 a.m. or 7 p.m. to midnight	Conservation Stage since Sept. 2, 2025: automatic systems 1 day a week; hose-end sprinklers 2 days	Austin Water watering day page
SAWS, San Antonio	5 to 10 a.m. and 9 p.m. to midnight (Stage 2 and 3)	Once a week on your designated day; SAWS’s home page listed Stage 3 rules in effect on Oct. 19, 2026	SAWS drought rules; SAWS home page

The run-time caps change the math. Los Angeles allows 8 minutes per station on 3 days, or 24 minutes a week; at a spray nozzle’s 1.58 in/hr that is about 0.63 inch a week. SNWA in Las Vegas recommends 12 minutes per watering day split into three 4-minute cycles at least an hour apart, which is cycle and soak written into a utility’s advice.

How can you tell if your lawn needs water or is overwatered?

Underwatered grass shows three signs: leaf blades fold lengthwise, the color shifts to blue-gray, and footprints stay visible long after you walk across it, according to UF/IFAS Extension. Overwatered lawns show runoff, puddles, shallow roots and weeds such as dollarweed and sedges. A screwdriver that slides 4 to 6 inches into the soil means the root zone still has water.

Dollarweed, nutsedge and annual bluegrass are the weeds extension guides tie most often to wet soil; our common lawn weeds chart shows how to tell them apart.

Sign	What it means	What to do	Source
Leaf blades folded lengthwise	Water stress	Water 1/2 to 3/4 inch	UF/IFAS LH025
Blue-gray or bluish-green tint	Early water stress	Water now; no benefit to watering earlier	Purdue AY-7
Footprints or tire tracks stay visible	Early water stress	Water, then wait until footprints show again	NC DEQ
Grayish-green and wilted	Advanced stress	Water without delay	Purdue AY-7
Brown leaves after weeks of drought	Dormancy; crowns usually alive for 4 to 6 weeks	1 to 1.5 inches every 4 to 6 weeks	Purdue AY-7
Screwdriver slides in 4 to 6 inches	Soil still moist	Skip this watering	NC State AG-367
Water running onto the street or sidewalk	Applied faster than soil absorbs	Shorten cycles; add soak time	Texas A&M AgriLife
Dollarweed and sedges spreading	Chronic overwatering	Cut frequency; water only at stress signs	UF/IFAS LH025
Crabgrass, disease, shallow roots	Overwatering	Water deeply and less often	Purdue AY-7

What do lawn watering guides get wrong?

Several top-ranking watering guides repeat rules of thumb that the primary sources contradict or narrow. The four most common: that midday watering burns grass, that every lawn needs 1 to 1.5 inches a week, that 20 or 30 minutes per zone is a standard run time, and that evening watering is wrong everywhere. The table sets each claim beside what the source documents say.

Common claim in lawn guides	What the primary source says	Source
Watering in midday sun burns the grass	Midday watering “does not cause the turf to burn”; it only wastes water to evaporation. Drops on smooth leaves did not burn them in a 2010 optics study	Purdue AY-7; New Phytologist, 2010
Every lawn needs 1 to 1.5 inches a week	July need for cool-season grass ranges from 1.18 inches (Southern California coast) to 2.52 inches (Southern California deserts); Minnesota lawns may need only 1/2 inch	UC IPM; University of Minnesota
Run each zone 20 to 30 minutes	20 minutes applies about 0.53 inch from a spray nozzle at 1.58 in/hr but 0.13 inch from a rotary nozzle at 0.4 in/hr	Rain Bird; Hunter; our arithmetic
Never water in the evening	Colorado State names 9 p.m. to 9 a.m.; Denver Water says night watering is fine in Colorado’s low humidity. The risk is humid nights above 68°F	CSU Extension; NC State AG-367
Buffalograss is a cool-season grass	K-State lists buffalograss with the warm-season grasses and as the least frequently watered lawn grass	K-State MF2059

Should you water today, and how?

Water only when the lawn or the soil says so, then apply the full 1/2 to 1 inch in the early morning. Check rain first (1/2 inch or more resets the clock), then soil moisture at 4 to 6 inches, then stress signs, then soil type, which decides whether one run is enough or the water needs cycle and soak. The table and flowchart hold the same rules.

If your situation is	Do this	Why (source)
1/2 inch or more of rain fell in the past few days	Skip watering until stress signs return	Rain of 1/2 to 3/4 inch resets the interval (UF/IFAS LH025)
A screwdriver slides 4 to 6 inches into the soil	Wait and recheck in 1 to 2 days	Root zone is still moist (NC State AG-367)
Grass is severely wilted	Water now, any hour	Wilted turf recovers fast if watered without delay (Purdue AY-7; K-State MF2059)
Clay soil or slope, water runs off before 1/2 inch	Cycle and soak: 1/4 inch per cycle, 30 to 60 minute rests	Intake as low as 0.2 in/hr on compacted clay (K-State MF2059; CSU; Denver Water)
Sandy soil	About 1/2 inch every third day	Sand holds less water (NC State AG-381)
Humid region with nights above 68°F	Water only between 2 and 8 a.m.	Brown patch turns severe (NC State AG-367)
Dry Western climate, low humidity	Night or early morning, 9 p.m. to 9 a.m.	Less evaporation; low disease risk (CSU Extension; Denver Water)
Afternoon above 90°F, lawn not wilted	Optional 5 to 10 minute cooling run per zone	Reduces summer patch symptoms (Nebraska Extension)
Your utility bans midday watering or limits days	Follow the assigned days and hours first	Fines apply, for example $100 to $600 in Los Angeles (LADWP)
Otherwise, lawn shows stress	Apply 1/2 to 1 inch in one early-morning run, 4 to 8 a.m.	Purdue AY-7; NC State AG-367

1. 1Has 1/2 inch or more of rain fallen in the past few days?

   YesSkip watering until the grass shows stress again (UF/IFAS LH025).

   NoGo to the next question

2. 2Does a screwdriver slide 4 to 6 inches into the soil?

   YesWait. The root zone is still moist; recheck in 1 to 2 days (NC State AG-367).

   NoGo to the next question

3. 3Is the grass severely wilted right now?

   YesWater now, whatever the hour (K-State MF2059; Purdue AY-7).

   NoGo to the next question

4. 4Is the grass still green and springing back after you walk on it?

   YesWait. There is no benefit to watering before stress signs appear (Purdue AY-7).

   NoGo to the next question

5. 5Is the soil clay, or is the lawn on a slope where water runs off?

   YesCycle and soak between 4 and 8 a.m.: 1/4 inch per cycle with 30 to 60 minute rests, 1/2 to 3/4 inch in total (CSU; Denver Water).

   NoGo to the next question

6. 6Is the soil sandy?

   YesApply about 1/2 inch early in the morning and expect to repeat every third day (NC State AG-381).

   NoApply 1/2 to 1 inch in one run between 4 and 8 a.m. on a day your utility allows (Purdue AY-7; NC State AG-367).

Source: UF/IFAS LH025; NC State AG-367 and AG-381; K-State MF2059; Purdue AY-7; CSU Extension; Denver Water

New seed and new sod are the exception to deep, infrequent watering. Purdue AY-7 keeps a seedbed moist 1 to 2 inches deep with 2 to 4 light waterings a day, and new sod gets 1 or 2 a day until roots take hold. Our guide to grass seed germination time covers that schedule, and sod installation cost covers new sod. For the rest of the year’s tasks, see the lawn care schedule and our turf and trees hub.