ZIP 59638 · Helena, MT · Nov 11, 2026

Soil temperature for ZIP code 59638

43°Faverage today, 0–4 in deep (modelled)
low 40°F · high 48°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 12.2 km from the ZIP centre point

On a week ago
6° warmer
37°F on Nov 4
5-day mean
42°F
what the verdicts use
Held 55°F last spring
Jun 16
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°38°
View as table
DayAverageLowHigh
Nov 436.6°F35.2°F39.2°Fanalysis
Nov 537.0°F34.5°F39.8°Fanalysis
Nov 637.2°F35.2°F40.3°Fanalysis
Nov 740.2°F36.8°F45.9°Fanalysis
Nov 842.1°F38.8°F47.2°Fanalysis
Nov 942.7°F40.2°F45.3°Fanalysis
Nov 1041.8°F40.0°F45.2°Fanalysis
Today43.1°F40.4°F47.5°Fanalysis
Nov 1242.8°F40.4°F45.7°Fforecast
Nov 1340.5°F37.9°F43.7°Fforecast
Nov 1440.3°F37.7°F44.2°Fforecast
Nov 1539.0°F36.8°F41.5°Fforecast
Nov 1636.4°F34.4°F39.5°Fforecast
Nov 1738.4°F36.4°F41.6°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 lettuceMar 21
50°FPre-emergent window opensMay 24
55°FCrabgrass can germinateJun 16
60°FTomatoesnot reached
65°FWarm-season grass seednot reached

Helena, MT, 26 km away: the full city page, with the 2026 season chart, growing degree days and nearby cities →

Nearby ZIP codes

Today's modelled average.

59634 47°F · 59632 43°F · 59601 43°F · 59623 47°F · 59625 47°F · 59635 44°F · 59631 40°F · 59636 47°F

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

Questions

What is the soil temperature in ZIP code 59638 today?
About 43°F on average in the top 4 inches (0–10 cm), low 40°F and high 48°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 12.2 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 59638?
The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 24 and 55°F from Jun 16.

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).