What is the soil temperature in ZIP code 81621 today?

About 40°F on average in the top 4 inches (0–10 cm), low 37°F and high 44°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 17.2 km from the ZIP centre, not a reading from your yard.

Is it time for crabgrass preventer in 81621?

The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 28 and 55°F from Jun 5.

ZIP 81621 · Aspen, CO · Nov 11, 2026

Soil temperature for ZIP code 81621

40°Faverage today, 0–4 in deep (modelled)
low 37°F · high 44°F

Modelled by NOAA GFS, not measured · run Nov 11, 12:00 UTC (7 am Eastern) · grid cell 17.2 km from the ZIP centre point

On a week ago

2° warmer

37°F on Nov 4

5-day mean

39°F

what the verdicts use

Held 55°F last spring

Jun 5

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 lettuceToo cold

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	37.1°F	36.8°F	37.2°F	analysis
Nov 5	37.1°F	35.5°F	40.6°F	analysis
Nov 6	38.8°F	36.8°F	41.5°F	analysis
Nov 7	38.6°F	37.2°F	40.4°F	analysis
Nov 8	38.4°F	37.0°F	41.4°F	analysis
Nov 9	39.9°F	37.1°F	45.5°F	analysis
Nov 10	40.9°F	37.2°F	45.5°F	analysis
Today	39.6°F	36.9°F	44.0°F	analysis
Nov 12	40.0°F	36.8°F	45.6°F	forecast
Nov 13	39.6°F	36.6°F	43.4°F	forecast
Nov 14	38.4°F	35.9°F	41.2°F	forecast
Nov 15	39.0°F	37.7°F	40.2°F	forecast
Nov 16	36.7°F	34.9°F	38.5°F	forecast
Nov 17	36.7°F	34.9°F	40.3°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 19
50°F	Pre-emergent window opens	May 28
55°F	Crabgrass can germinate	Jun 5
60°F	Tomatoes	not reached
65°F	Warm-season grass seed	not reached

Nearby ZIP codes

Today's modelled average.

81656 40°F · 81615 40°F · 81654 40°F · 81642 31°F · 81623 40°F · 81631 40°F · 81611 40°F · 81632 35°F

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

Questions

What is the soil temperature in ZIP code 81621 today?: About 40°F on average in the top 4 inches (0–10 cm), low 37°F and high 44°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 17.2 km from the ZIP centre, not a reading from your yard.
Is it time for crabgrass preventer in 81621?: The spring window is closed. It opens again when the soil holds 50°F. Last spring the soil held 50°F from May 28 and 55°F from Jun 5.

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).