What is the soil temperature in ZIP code 59421 today?

About 45°F on average in the top 4 inches (0–10 cm), low 43°F and high 49°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 9.5 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 59421?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Jun 15 and 55°F from Jun 18.

ZIP 59421 · Montana · Nov 11, 2026

Soil temperature for ZIP code 59421

45°Faverage today, 0–4 in deep (modelled)
low 43°F · high 49°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 9.5 km from the ZIP centre point

On a week ago

7° warmer

38°F on Nov 4

5-day mean

44°F

what the verdicts use

Held 55°F last spring

Jun 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	38.0°F	35.2°F	43.1°F	analysis
Nov 5	38.6°F	36.4°F	41.1°F	analysis
Nov 6	38.3°F	36.2°F	41.4°F	analysis
Nov 7	43.5°F	41.8°F	46.7°F	analysis
Nov 8	44.5°F	42.3°F	47.2°F	analysis
Nov 9	42.2°F	40.4°F	44.7°F	analysis
Nov 10	42.9°F	41.7°F	45.3°F	analysis
Today	45.2°F	43.1°F	48.8°F	analysis
Nov 12	46.0°F	44.3°F	48.4°F	forecast
Nov 13	44.0°F	42.4°F	45.9°F	forecast
Nov 14	43.0°F	41.1°F	45.2°F	forecast
Nov 15	39.7°F	37.5°F	42.2°F	forecast
Nov 16	39.7°F	37.9°F	42.5°F	forecast
Nov 17	40.2°F	39.0°F	42.0°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 20
50°F	Pre-emergent window opens	Jun 15
55°F	Crabgrass can germinate	Jun 18
60°F	Tomatoes	not reached
65°F	Warm-season grass seed	not reached

Great Falls, MT, 56 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

This ZIP code area covers about 747 square miles; the reading is for the model grid cell nearest its Census centre point, which can be far from where you are. Try a neighbouring ZIP if it looks off.

Nearby ZIP codes

Today's modelled average.

59405 49°F · 59648 44°F · 59485 49°F · 59602 43°F · 59483 48°F · 59477 47°F · 59472 49°F · 59480 50°F

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

Questions

What is the soil temperature in ZIP code 59421 today?: About 45°F on average in the top 4 inches (0–10 cm), low 43°F and high 49°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 9.5 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 59421?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from Jun 15 and 55°F from Jun 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).