Current soil temperature: 68°F at the 2-inch depth, 0.2°F below the historical average for this date. Modeled estimate for July 4, 2026; the nearest sensor station is more than 75 miles away.
68
No sensor station within 75 miles.This reading is a modeled estimate from Open-Meteo's ERA5-Land archive.
Planning the year
See San Mateo scheduleThere's no seasonal lawn-care action due for your area today. See your city's full lawn-care schedule for what's coming up, or use the current soil conditions and chart below.
When to come back
The recommendation window typically opens when the 3-day soil temperature average reaches the trigger temperature. Bookmark this page and check back in a week.
Source: Open-Meteo ERA5-Land modeled estimate
Depth: 2" • 28 days of data • Estimated, Open-Meteo
Merced 23 WSW (Site USCRN-93243), CA
Estimated Soil Temperatures
| Date | 2" °F | Δ 2" | 8" °F | 20" °F |
|---|---|---|---|---|
| Jul 4 | 67.7 | -0.2 | 67.3 | 65.9 |
| Jul 3 | 67.9 | +0.4 | 67.2 | 65.9 |
| Jul 2 | 67.5 | +0.6 | 67.0 | 65.8 |
| Jul 1 | 66.9 | -1.0 | 66.9 | 65.9 |
| Jun 30 | 67.9 | -1.0 | 67.7 | 65.8 |
| Jun 29 | 68.9 | +0.7 | 67.9 | 65.5 |
| Jun 28 | 68.2 | — | 66.5 | 65.3 |
Soil temperature by depth
Estimated soil temperatures for this location provided by Open-Meteo.
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 for your area.
Readings refresh nightly from the USDA-NRCS Soil Climate Analysis Network and the NOAA US Climate Reference Network (USCRN). Where no station is within 75 miles, readings are modeled estimates from Open-Meteo’s ERA5-Land archive rather than direct sensor measurements; 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.
Zone 10A
October 22
1,620 ft
Warm-season only
This area favors warm-season grasses; cool-season grass struggles through the summer heat here. As of July 5, the 2-inch soil temperature is tracking the 10-year normal for this date. No federal soil station is close enough for direct readings, so values here are modeled from the nearest Open-Meteo grid cell. Use as a directional guide.
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.
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.
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.
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.
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.
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.
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 San Mateo, CA: 68°F at 2 inches, as of July 4, 2026. Modeled estimate.
| Grass species | Germination optimum | Days | Right now |
|---|---|---|---|
| Bermudagrass | 75–85°F | 10-30 | Germinates slowly |
| Zoysia | 75–85°F | varies | Germinates slowly |
| Buffalograss | 75–85°F | 14-30 | Germinates slowly |
| Centipede | 75–85°F | varies | Germinates slowly |
| Kentucky bluegrass | 59–86°F | 14-30 | Germinates, but warm for establishment |
This week’s watering for San Mateo, CA
Water about 1 inch this week
| Weekly target | 1 in | at 68°F soil, for warm-season grass |
|---|---|---|
| Expected rain | 0 in | over the next 7 days |
| You supply | 1 in | in 1 deep session, 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. 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 San Mateo, CA 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 |
|---|---|---|
| Dollar spot (Clarireedia jacksonii) | Favorable | 7 of the next 7 days sit in its 60-85°F window; worse on underfed turf. Keep adequate nitrogen and remove morning dew (early mowing or dragging a hose) to shorten the wetness window. |
How temperature drives lawn disease, and the cultural fixes →
Growing degree days near San Mateo, CA
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 Merced 23 WSW.
What growing degree days are and how to use them for lawn-care timing →