What is the soil temperature in ZIP code 91978 today?

About 78°F on average in the top 4 inches (0–10 cm), low 72°F and high 85°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 8.6 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 91978?

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 91978 · Rancho San Diego, CA · Nov 11, 2026

Soil temperature for ZIP code 91978

78°Faverage today, 0–4 in deep (modelled)
low 72°F · high 85°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 8.6 km from the ZIP centre point

On a week ago

6° warmer

72°F on Nov 4

5-day mean

77°F

what the verdicts use

Held 55°F last spring

All winter

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	72.2°F	67.9°F	78.8°F	analysis
Nov 5	72.7°F	67.4°F	79.9°F	analysis
Nov 6	74.0°F	68.1°F	82.6°F	analysis
Nov 7	75.5°F	69.0°F	85.0°F	analysis
Nov 8	76.9°F	70.6°F	85.8°F	analysis
Nov 9	77.5°F	71.5°F	85.4°F	analysis
Nov 10	77.6°F	71.8°F	85.7°F	analysis
Today	77.7°F	72.1°F	85.2°F	analysis
Nov 12	76.4°F	71.4°F	82.4°F	forecast
Nov 13	73.3°F	70.3°F	75.9°F	forecast
Nov 14	70.0°F	67.8°F	72.4°F	forecast
Nov 15	70.8°F	66.3°F	77.4°F	forecast
Nov 16	71.2°F	67.1°F	76.5°F	forecast
Nov 17	67.6°F	65.8°F	69.2°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	never below
60°F	Tomatoes	Jan 14
65°F	Warm-season grass seed	Jan 30

Lakeside, CA, 18 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

91914 78°F · 91977 78°F · 91902 78°F · 91915 77°F · 91941 78°F · 91913 77°F · 91945 78°F · 92019 67°F

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

Questions

What is the soil temperature in ZIP code 91978 today?: About 78°F on average in the top 4 inches (0–10 cm), low 72°F and high 85°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 8.6 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 91978?: 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).