What is the soil temperature in ZIP code 06439 today?

About 49°F on average in the top 4 inches (0–10 cm), low 46°F and high 50°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 12.6 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 06439?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 6 and 55°F from May 18.

ZIP 06439 · East Haddam, CT · Nov 11, 2026

Soil temperature for ZIP code 06439

49°Faverage today, 0–4 in deep (modelled)
low 46°F · high 50°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 12.6 km from the ZIP centre point

On a week ago

8° cooler

57°F on Nov 4

5-day mean

51°F

what the verdicts use

Held 55°F last spring

May 18

crabgrass germination temperature

What the soil says today

Pre-emergentSeason over
Cool-season seedToo late in the season
Warm-season seedToo cold
TomatoesToo cold
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	56.7°F	53.7°F	59.5°F	analysis
Nov 5	59.6°F	57.3°F	62.3°F	analysis
Nov 6	62.1°F	61.8°F	62.4°F	analysis
Nov 7	58.9°F	57.3°F	60.6°F	analysis
Nov 8	52.3°F	51.2°F	53.4°F	analysis
Nov 9	49.0°F	47.4°F	49.8°F	analysis
Nov 10	47.9°F	45.2°F	49.8°F	analysis
Today	48.8°F	46.3°F	50.3°F	analysis
Nov 12	48.5°F	47.0°F	49.2°F	forecast
Nov 13	45.2°F	42.9°F	47.6°F	forecast
Nov 14	41.4°F	40.8°F	42.0°F	forecast
Nov 15	40.1°F	37.8°F	41.7°F	forecast
Nov 16	40.3°F	37.5°F	42.6°F	forecast
Nov 17	40.5°F	38.6°F	42.1°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	Mar 26
50°F	Pre-emergent window opens	May 6
55°F	Crabgrass can germinate	May 18
60°F	Tomatoes	Jun 6
65°F	Warm-season grass seed	Jun 10

Madison, CT, 22 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

06423 49°F · 06426 49°F · 06412 49°F · 06409 49°F · 06417 49°F · 06442 49°F · 06371 49°F · 06438 49°F

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

Questions

What is the soil temperature in ZIP code 06439 today?: About 49°F on average in the top 4 inches (0–10 cm), low 46°F and high 50°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 12.6 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 06439?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 6 and 55°F from May 18.

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).