What is the soil temperature in ZIP code 92821 today?

About 74°F on average in the top 4 inches (0–10 cm), low 69°F and high 82°F, from NOAA's GFS model run of Nov 11, 12:00 UTC (7 am Eastern). It is a model value for a grid cell 13 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 92821?

Soil here stayed above 50°F all last winter, so the 50 to 55°F soil rule gives no spring window. Time pre-emergent to your local calendar.

ZIP 92821 · Brea, CA · Nov 11, 2026

Soil temperature for ZIP code 92821

74°Faverage today, 0–4 in deep (modelled)
low 69°F · high 82°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 13 km from the ZIP centre point

On a week ago

6° warmer

68°F on Nov 4

5-day mean

74°F

what the verdicts use

Held 55°F last spring

Feb 23

crabgrass germination temperature

What the soil says today

Pre-emergentSeason over
Cool-season seedToo late in the season
Warm-season seedWarm enough
TomatoesSoil warm enough
Peas and lettuceWarm enough

From the 5-day mean of the modelled 0–4 in layer.

Soil temperature, 0–4 in: last 7 days and next 7

°F, modelled. Dots and line: daily average (dashed = forecast); bars: low to high; green band: 50–55°F.

View as table

Day	Average	Low	High
Nov 4	68.5°F	63.1°F	76.4°F	analysis
Nov 5	69.8°F	64.2°F	77.8°F	analysis
Nov 6	70.7°F	64.9°F	79.1°F	analysis
Nov 7	72.4°F	67.0°F	80.9°F	analysis
Nov 8	73.9°F	67.8°F	83.1°F	analysis
Nov 9	75.0°F	69.2°F	83.8°F	analysis
Nov 10	74.9°F	69.2°F	83.0°F	analysis
Today	74.3°F	68.8°F	82.0°F	analysis
Nov 12	73.3°F	68.1°F	79.9°F	forecast
Nov 13	71.4°F	67.8°F	76.1°F	forecast
Nov 14	67.6°F	65.2°F	69.2°F	forecast
Nov 15	68.1°F	64.1°F	74.8°F	forecast
Nov 16	68.3°F	64.2°F	73.4°F	forecast
Nov 17	65.6°F	64.4°F	67.1°F	forecast

Source: NOAA NCEP GFS 0.25°, 0–10 cm soil temperature, run Nov 11, 12:00 UTC (7 am Eastern).

Spring 2026 threshold dates

From the 5-day mean held for 10 days or more.

Soil	What it means	Held from (spring 2026)
40°F	Peas and lettuce	never below
50°F	Pre-emergent window opens	never below
55°F	Crabgrass can germinate	Feb 23
60°F	Tomatoes	Jan 15
65°F	Warm-season grass seed	Feb 2

Anaheim, CA, 12 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

92870 74°F · 92835 78°F · 92823 74°F · 91748 78°F · 92831 78°F · 92886 74°F · 91765 74°F · 90631 78°F

More: crabgrass timing in California · every California city · how accurate the model is.

Questions

What is the soil temperature in ZIP code 92821 today?: About 74°F on average in the top 4 inches (0–10 cm), low 69°F and high 82°F, from NOAA's GFS model run of Nov 11, 12:00 UTC (7 am Eastern). It is a model value for a grid cell 13 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 92821?: Soil here stayed above 50°F all last winter, so the 50 to 55°F soil rule gives no spring window. Time pre-emergent to your local calendar.

Data: Global Forecast System (GFS) 0.25°, soil temperature 0–10 cm (TSOIL) (NOAA National Centers for Environmental Prediction (NCEP)); 2025 Gazetteer ZIP Code Tabulation Areas (ZCTA) and 2024 cartographic boundary state outlines (U.S. Census Bureau).