Soil Temperature in Fremont, CA

Current soil temperature: 75°F at the 2-inch depth, 4°F below the historical average for this date. Measured July 3, 2026 at the Merced 23 WSW NOAA station, 65 miles away. Rising 2.1°F over the last 7 days.

SOIL TEMPERATURE · 2" DEPTH · JULY 3, 2026

4 degrees below historical average of 79 degrees Fahrenheit Rising 2.1°F over 7 days

2-inch depth (5 cm)

NOAA sensor #USCRN-93243 , 65 miles E (Merced 23 WSW)

Confidence: MediumStation is 65.3 mi from your location, so readings may not exactly match your conditions

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

Advanced options (year, as-of date)

Recommendations

Planning the year

See Fremont 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 75°F at 2 inches at the Merced 23 WSW sensor, 65 miles from your location.

Details for Summer iron (foliar) application
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 70°F
Source: Merced 23 WSW station

Source: Merced 23 WSW station

Daily Soil Temperature

Depth: 2" • Last 12 Months

Showing chart

Nearest USDA Station

Merced 23 WSW (Site USCRN-93243), CA

Distance: 65 miles from Fremont, CA
Elevation: 1620 ft
Coordinates: 37.2400, -120.8800

NOAA USCRN soil temperature observations.

The 2-inch reading first crossed 50°F on Jun 23, when the pre-emergent window opened.
Date	2" °F	Δ 2"	4" °F	8" °F	20" °F	40" °F
Jul 3	74.8	+0.9	72.5	69.8	69.4	68.7
Jul 2	73.9	+0.3	71.8	69.6	69.3	68.5
Jul 1	73.6	+0.2	71.6	69.6	69.3	68.5
Jun 30	73.4	+1.4	71.4	69.3	68.9	68.4
Jun 29	72.0	+0.8	70.5	68.9	68.7	68.4
Jun 28	71.2	-1.5	70.2	69.3	68.9	68.5
Jun 27	72.7	—	71.2	69.6	69.1	68.7

Soil temperature by depth

74.8°F

2 in · germination

72.5°F

4 in · root zone

69.8°F

8 in · deeper trend

69.4°F

20 in · deep soil

68.7°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 Fremont, CA

USDA Growing Zone

Zone 9B

Average First Frost

October 22

Elevation

1,620 ft

Cool-Season Viability

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 running 4°F below the 10-year normal for this date. Readings come from the Merced 23 WSW NOAA research-grade station, 65 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 Fremont, CA: 75°F at 2 inches, as of July 3, 2026.

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

See all species and the full germination guide →

This week’s watering for Fremont, CA

Water about 1.25 inches this week

Weekly target	1.25 in	at 75°F soil, for warm-season grass
Expected rain	0 in	over the next 7 days
You supply	1.25 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. 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 Fremont, 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	6 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 Fremont, CA

241GDD (base 50°F) since January 1, through July 3

75°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 Merced 23 WSW.

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