What is the soil temperature in ZIP code 52621 today?

About 51°F on average in the top 4 inches (0–10 cm), low 49°F and high 53°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 5.4 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 52621?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Apr 11 and 55°F from May 12.

ZIP 52621 · Washington, IA · Nov 11, 2026

Soil temperature for ZIP code 52621

51°Faverage today, 0–4 in deep (modelled)
low 49°F · high 53°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 5.4 km from the ZIP centre point

On a week ago

6° cooler

58°F on Nov 4

5-day mean

49°F

what the verdicts use

Held 55°F last spring

May 12

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	57.5°F	55.0°F	61.1°F	analysis
Nov 5	51.8°F	51.0°F	52.7°F	analysis
Nov 6	48.5°F	47.6°F	50.3°F	analysis
Nov 7	43.9°F	40.8°F	47.1°F	analysis
Nov 8	47.0°F	42.7°F	52.3°F	analysis
Nov 9	49.4°F	44.9°F	54.5°F	analysis
Nov 10	52.3°F	49.4°F	54.9°F	analysis
Today	51.4°F	49.2°F	53.0°F	analysis
Nov 12	46.4°F	44.5°F	49.8°F	forecast
Nov 13	39.6°F	38.2°F	40.8°F	forecast
Nov 14	38.3°F	37.2°F	41.0°F	forecast
Nov 15	39.4°F	36.2°F	43.1°F	forecast
Nov 16	40.7°F	37.0°F	44.6°F	forecast
Nov 17	41.8°F	38.2°F	45.2°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	Mar 6
50°F	Pre-emergent window opens	Apr 11
55°F	Crabgrass can germinate	May 12
60°F	Tomatoes	May 25
65°F	Warm-season grass seed	May 28

Muscatine, IA, 47 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

52647 51°F · 52659 51°F · 52652 52°F · 52201 51°F · 52654 52°F · 52737 51°F · 52738 51°F · 52353 52°F

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

Questions

What is the soil temperature in ZIP code 52621 today?: About 51°F on average in the top 4 inches (0–10 cm), low 49°F and high 53°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 5.4 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 52621?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Apr 11 and 55°F from May 12.

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).