What is the soil temperature in ZIP code 51640 today?

About 55°F on average in the top 4 inches (0–10 cm), low 53°F and high 58°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 15.7 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 51640?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Mar 21 and 55°F from Apr 13.

ZIP 51640 · Shenandoah, IA · Nov 11, 2026

Soil temperature for ZIP code 51640

55°Faverage today, 0–4 in deep (modelled)
low 53°F · high 58°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 15.7 km from the ZIP centre point

On a week ago

1° warmer

54°F on Nov 4

5-day mean

52°F

what the verdicts use

Held 55°F last spring

Apr 13

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	53.9°F	52.8°F	55.3°F	analysis
Nov 5	52.8°F	51.8°F	53.6°F	analysis
Nov 6	48.4°F	46.0°F	51.0°F	analysis
Nov 7	46.2°F	42.4°F	51.3°F	analysis
Nov 8	51.1°F	47.4°F	56.2°F	analysis
Nov 9	53.5°F	48.5°F	60.0°F	analysis
Nov 10	55.5°F	51.6°F	59.4°F	analysis
Today	55.3°F	53.0°F	57.6°F	analysis
Nov 12	49.8°F	48.3°F	52.7°F	forecast
Nov 13	42.8°F	39.5°F	45.2°F	forecast
Nov 14	40.3°F	36.6°F	44.1°F	forecast
Nov 15	42.4°F	40.7°F	44.8°F	forecast
Nov 16	43.5°F	39.7°F	48.2°F	forecast
Nov 17	45.4°F	41.7°F	49.8°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	Feb 10
50°F	Pre-emergent window opens	Mar 21
55°F	Crabgrass can germinate	Apr 13
60°F	Tomatoes	May 12
65°F	Warm-season grass seed	May 27

Omaha, NE, 74 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

51650 54°F · 64496 55°F · 68421 55°F · 51652 54°F · 51648 55°F · 68410 55°F · 51639 54°F · 68379 55°F

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

Questions

What is the soil temperature in ZIP code 51640 today?: About 55°F on average in the top 4 inches (0–10 cm), low 53°F and high 58°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 15.7 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 51640?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Mar 21 and 55°F from Apr 13.

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).