Longmont, CO Weather & Growing Conditions
Tonight
34°F
Partly Cloudy
Partly cloudy, with a low around 34. West wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 34°F | Partly Cloudy | 2 mph W | 0% |
| Wednesday | 55°F | Partly Sunny | 0 to 5 mph NE | 7% |
| Wednesday Night | 34°F | Mostly Cloudy | 3 mph NW | 8% |
| Thursday | 58°F | Sunny | 1 to 5 mph S | 0% |
| Thursday Night | 36°F | Partly Cloudy | 3 mph WSW | 1% |
| Friday | 57°F | Mostly Sunny | 1 to 5 mph S | 10% |
| Friday Night | 34°F | Mostly Clear | 5 mph W | 10% |
| Saturday | 59°F | Sunny | 1 to 6 mph SSW | 0% |
| Saturday Night | 34°F | Mostly Clear | 5 mph W | 0% |
| Sunday | 66°F | Sunny | 3 mph SSW | 0% |
| Sunday Night | 41°F | Mostly Clear | 3 to 8 mph W | 0% |
| Monday | 66°F | Mostly Sunny | 1 to 6 mph E | 0% |
| Monday Night | 40°F | Partly Cloudy | 3 mph WNW | 0% |
| Tuesday | 64°F | Mostly Sunny | 3 mph S | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Longmont, CO
Last spring frost
May 7
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
6a
Explore more for Longmont, CO: full frost dates · planting calendar · Colorado frost dates
Climate data from the nearest NOAA station, Longmont 2 Ese, Co (7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.