Soil Temperature in Douglas, AZ

Current soil temperature: 87°F at the 2-inch depth, 5.4°F above the historical average for this date. Measured July 3, 2026 at the Walnut Gulch #1 USDA station, 40 miles away. Falling 2.6°F over the last 7 days.

SOIL TEMPERATURE · 2" DEPTH · JULY 3, 2026

5.4 degrees above historical average of 82 degrees Fahrenheit Falling 2.6°F over 7 days

2-inch depth (5 cm)

USDA sensor #2026 , 40 miles NW (Walnut Gulch #1)

Confidence: MediumStation is 39.8 mi from your location, so readings may not exactly match your conditions

Last reading: July 3, 2026 (updated 2 days ago). USDA sensors publish with about a 1-day lag.

Advanced options (year, as-of date)

Recommendations

Planning the year

See Douglas schedule

Fertilizer

IN WINDOW

Summer iron (foliar) application

A foliar iron spray darkens the lawn's color without forcing the leaf growth a nitrogen feeding would, which is exactly what summer-stressed turf needs. Iron is taken up directly through the leaves, so results show in days rather than weeks. Shallow soil temperatures are in the action band at 87°F at 2 inches at the Walnut Gulch #1 sensor, 40 miles from your location.

Details for Summer iron (foliar) application
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 70°F
Source: Walnut Gulch #1 station

Source: Walnut Gulch #1 station

Lawn Care

IN WINDOW

Summer drought-stress watering (cool-season)

Cool-season grass slips into protective summer dormancy when soil dries out, and prolonged dormancy can kill the crown. A deep weekly soak (about an inch of water) keeps the crown alive without encouraging shallow roots the way light, daily watering would. Shallow soil temperatures are in the action band at 87°F at 2 inches at the Walnut Gulch #1 sensor, 40 miles from your location.

Details for Summer drought-stress watering (cool-season)
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 80°F
Source: Walnut Gulch #1 station

Source: Walnut Gulch #1 station

Daily Soil Temperature

Depth: 2" • Last 12 Months

Showing chart

Nearest USDA Station

Walnut Gulch #1 (Site 2026), AZ

Distance: 40 miles from Douglas, AZ
Elevation: 4500 ft
Coordinates: 31.7333, -110.0500

USDA NWCC AWDB soil temperature observations.

The 2-inch reading first crossed 50°F on Nov 22, when the pre-emergent window opened.
Date	2" °F	Δ 2"	4" °F	8" °F	20" °F	40" °F
Jul 3	87.4	+1.6	93.2	92.1	87.8	83.1
Jul 2	85.8	+0.5	93.2	92.5	88.0	83.1
Jul 1	85.3	-2.5	92.8	92.8	88.3	82.9
Jun 30	87.8	-0.7	93.6	93.0	88.3	82.9
Jun 29	88.5	+1.1	93.6	92.7	88.3	82.8
Jun 28	87.4	-2.6	93.2	92.8	88.3	82.6
Jun 27	90.0	—	94.5	93.4	88.2	82.6

Soil temperature by depth

87.4°F

2 in · germination

93.2°F

4 in · root zone

92.1°F

8 in · deeper trend

87.8°F

20 in · deep soil

83.1°F

40 in · frost depth

Check the current soil temp at your location, or open the live US soil temperature mapto see today’s ground readings from 380+ USDA and NOAA stations across the country. Enter your ZIP code for live soil temperatures near you, plus planting windows, pre-emergent timing, fertilizer guidance, and disease watch alerts based on your nearest USDA monitoring station.

How Soil Temperature Drives Lawn Timing

About the Data

Readings refresh nightly from the USDA-NRCS Soil Climate Analysis Network and the NOAA US Climate Reference Network (USCRN). Readings are measured by in-ground sensors at federal monitoring stations, not estimated from weather models; see how we measure. Planting windows are derived from multi-year climatology overlaid with NOAA 1991–2020 frost normals. Recommendation cards evaluate current soil conditions against research-backed thresholds from university extension sources. Check back regularly as conditions change. The guidance updates with every new reading.

Data sources: USDA-NRCS SCAN network, NOAA USCRN, NOAA 1991–2020 climate normals, and localized frost climatology via Soil Temps analytics.

Browse soil temperature data by state, over 2,000 cities with current readings, hardiness zones, and planting windows.

Explore the US Soil Temperature Map for a live station view of readings across the country.

Soil Conditions in Douglas, AZ

USDA Growing Zone

Zone 8A

Average First Frost

October 22

Elevation

4,500 ft

Cool-Season Viability

Transition zone

In the transition zone, tall fescue is your best cool-season option. As of July 5, the 2-inch soil temperature is running 5°F above the 10-year normal for this date. With an average first frost of October 22 and an elevation of 4,500 feet, your fall seeding window timing is shaped by both soil temperature trends and frost risk. Zone 8a soils rarely stay below the 55°F pre-emergent threshold for long, so monitoring for early crabgrass flush is critical. Data comes from the USDA station at Walnut Gulch #1, 40 mi away.

For established lawns and gardens, the 4 inch soil temperature is a more useful reading than the surface. This 4-inch root-zone depth changes more slowly than the 2-inch surface layer, so it is a steadier signal for timing fertilizer, aeration, and weed control. The depths your nearest station reports are shown above; stations in the federal network typically report 2, 4, 8, 20, and 40 inches, while modeled estimates for areas far from a station cover fewer depths.

When to apply pre-emergent herbicide →

View historical soil temperature data →

Soil Temperature FAQ

What soil temperature is needed to plant grass seed?

Cool-season grasses like fescue and bluegrass germinate best when soil at 2 inches stays between 50–65°F for several consecutive days. Warm-season grasses like Bermuda and Zoysia need soil temperatures of 65–70°F or higher before seeding.

How deep should I measure soil temperature?

Use 2 inches for germination decisions, since that is where seeds sit. Use the 4 inch soil temperature for established lawn and garden timing: it reads the root zone, changes more slowly than the surface, and is the depth most fertilizer, aeration, and disease guidance references. The 8 inch reading shows deeper root-zone trend. The 20 and 40 inch readings track deep soil and frost depth where federal stations report them.

What does the 4 inch soil temperature mean?

The 4 inch soil temperature shows conditions deeper in the root zone than the 2 inch germination reading. It is commonly used for established lawn, garden, and agricultural timing because it changes more slowly than the surface layer, so it is a steadier signal for fertilizer, aeration, and weed-control decisions.

What’s the difference between soil temperature and air temperature?

Soil changes temperature much more slowly than air due to thermal mass. A warm afternoon does not mean the ground is warm. Soil temperature lags air temperature by days or weeks, making it a more reliable indicator of when biological processes like germination actually begin.

When should I apply pre-emergent based on soil temperature?

Apply pre-emergent herbicide when soil at 2 inches reaches 55°F for several consecutive days. This is the threshold where crabgrass and other summer annual weeds begin germinating. Applying after this point reduces effectiveness significantly.

What is a USDA Plant Hardiness Zone?

USDA Plant Hardiness Zones divide the US into 13 zones based on average annual extreme minimum temperature. They help determine which plants and grasses can survive winter in your area. Zone numbers increase from coldest (1a) to warmest (13b).

Grass seed germination

Your soil near Douglas, AZ: 87°F at 2 inches, as of July 3, 2026.

Grass species	Germination optimum	Days	Right now
Kentucky bluegrass	59–86°F	14-30	Too warm to establish
Tall fescue	68–86°F	7-12	Too warm to establish
Perennial ryegrass	68–86°F	5-10	Too warm to establish
Fine fescue	59–77°F	7-14	Too warm to establish
Bermudagrass	75–85°F	10-30	Too warm to establish

See all species and the full germination guide →

This week’s watering for Douglas, AZ

Water 0.65 inches, or let the lawn go dormant

Weekly target	1.5 in	at 87°F soil, for cool-season grass
Expected rain	0.85 in	over the next 7 days
You supply	0.65 in	in 2 deep sessions, watered 4-9 AM

The weekly target includes rainfall, so irrigation only covers the deficit. Water deeply and infrequently rather than a little every day: shallow daily watering builds shallow roots and invites disease. Above 85°F, a cool-season lawn can also stay dormant on about 1/2 inch every 2-3 weeks, just enough to keep the crowns alive. Rainfall is a modeled forecast estimate for this location.

How to water by soil temperature, and audit your sprinklers →

Lawn disease risk

The 7-day forecast near Douglas, AZ favors active disease pressure. These diseases are the ones to watch now. Based on a modeled weather estimate for this location.

Disease	Risk	Why now
Brown patch (Rhizoctonia solani)	Favorable	6 of the next 7 nights stay above 68°F with hot days; worse with excess nitrogen. Water only 4-8 AM so blades dry by evening, ease off quick-release nitrogen, and improve airflow.
Pythium blight (Pythium spp.)	Favorable	7 of the next 7 nights stay above 65°F with hot days; worse with excess nitrogen. Water early morning to limit leaf wetness, hold nitrogen to 0.25 lb/1,000 sq ft, and fix drainage in low spots. The fastest killer, 2-3 days.

How temperature drives lawn disease, and the cultural fixes →

Growing degree days near Douglas, AZ

2,211GDD (base 50°F) since January 1, through July 3

87°Fcurrent soil temperature

Growing degree days measure the heat a lawn has accumulated this year: each day adds the amount its average temperature runs above 50°F, the point where cool-season growth and most pests get going. Turf managers use the running total to time crabgrass pre-emergent, annual bluegrass seedhead suppression, and grub control. Pairing it with the current soil temperature shows both the season's heat so far and what the ground is doing right now. Measured at the NOAA station Elgin 5 S.

What growing degree days are and how to use them for lawn-care timing →