What is the soil temperature in ZIP code 50439 today?

About 50°F on average in the top 4 inches (0–10 cm), low 48°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 11.8 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 50439?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Apr 13 and 55°F from May 10.

ZIP 50439 · Clear Lake, IA · Nov 11, 2026

Soil temperature for ZIP code 50439

50°Faverage today, 0–4 in deep (modelled)
low 48°F · high 53°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 11.8 km from the ZIP centre point

On a week ago

1° cooler

52°F on Nov 4

5-day mean

48°F

what the verdicts use

Held 55°F last spring

May 10

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	51.8°F	48.8°F	55.5°F	analysis
Nov 5	48.7°F	48.0°F	49.6°F	analysis
Nov 6	44.8°F	41.5°F	47.0°F	analysis
Nov 7	43.3°F	39.5°F	47.7°F	analysis
Nov 8	47.0°F	43.6°F	50.9°F	analysis
Nov 9	48.0°F	43.2°F	53.8°F	analysis
Nov 10	50.0°F	45.4°F	54.1°F	analysis
Today	50.5°F	47.8°F	52.8°F	analysis
Nov 12	44.9°F	42.7°F	47.8°F	forecast
Nov 13	38.2°F	37.0°F	39.8°F	forecast
Nov 14	37.4°F	35.0°F	41.1°F	forecast
Nov 15	38.1°F	35.2°F	41.7°F	forecast
Nov 16	39.7°F	36.1°F	44.0°F	forecast
Nov 17	41.8°F	38.4°F	45.8°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	Mar 21
50°F	Pre-emergent window opens	Apr 13
55°F	Crabgrass can germinate	May 10
60°F	Tomatoes	May 25
65°F	Warm-season grass seed	May 27

Mason City, IA, 42 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

50449 51°F · 50421 51°F · 50457 51°F · 50447 50°F · 50479 51°F · 50438 51°F · 50420 51°F · 50470 51°F

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

Questions

What is the soil temperature in ZIP code 50439 today?: About 50°F on average in the top 4 inches (0–10 cm), low 48°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 11.8 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 50439?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Apr 13 and 55°F from May 10.

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).