ZIP 59640 · Helena Valley West Central, MT · Nov 11, 2026

Soil temperature for ZIP code 59640

43°Faverage today, 0–4 in deep (modelled)
low 42°F · high 46°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 9.2 km from the ZIP centre point

On a week ago
6° warmer
37°F on Nov 4
5-day mean
41°F
what the verdicts use
Held 55°F last spring
Jun 17
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.

30°40°50°60°50–55°F windowNov 4Nov 6Nov 8TodayNov 14Nov 1637°43°39°
View as table
DayAverageLowHigh
Nov 436.7°F35.4°F39.5°Fanalysis
Nov 536.6°F34.8°F39.3°Fanalysis
Nov 636.0°F35.0°F36.9°Fanalysis
Nov 738.9°F35.9°F44.3°Fanalysis
Nov 841.8°F38.6°F46.2°Fanalysis
Nov 940.6°F37.7°F44.4°Fanalysis
Nov 1040.6°F38.4°F43.9°Fanalysis
Today42.9°F41.6°F45.5°Fanalysis
Nov 1242.8°F40.8°F45.4°Fforecast
Nov 1340.5°F38.4°F42.9°Fforecast
Nov 1439.9°F37.3°F43.5°Fforecast
Nov 1538.3°F35.7°F42.2°Fforecast
Nov 1638.0°F35.5°F41.4°Fforecast
Nov 1739.1°F37.3°F41.9°Fforecast
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.

SoilWhat it meansHeld from (spring 2026)
40°FPeas and lettuceApr 6
50°FPre-emergent window opensMay 25
55°FCrabgrass can germinateJun 17
60°FTomatoesnot reached
65°FWarm-season grass seednot reached

Helena, MT, 32 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

59633 43°F · 59713 42°F · 59636 47°F · 59728 42°F · 59601 43°F · 59625 47°F · 59623 47°F · 59602 43°F

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

Questions

What is the soil temperature in ZIP code 59640 today?
About 43°F on average in the top 4 inches (0–10 cm), low 42°F and high 46°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 9.2 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 59640?
The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 25 and 55°F from Jun 17.

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).