Boulder, CO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Boulder, a city in Boulder County, Colorado.
Today
78°F
Patchy Smoke
Patchy smoke before noon, then patchy smoke and a slight chance of showers and thunderstorms. Mostly sunny, with a high near 78. East wind around 7 mph. Chance of precipitation is 20%.
7-day forecast for Boulder
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 78°F | Patchy Smoke | 7 mph E | 16% |
| Tonight | 56°F | Patchy Smoke | 2 to 7 mph NNE | 11% |
| Wednesday | 86°F | Patchy Smoke | 2 to 7 mph NE | 1% |
| Wednesday Night | 59°F | Mostly Clear | 2 to 6 mph NNW | 1% |
| Thursday | 95°F | Sunny | 2 to 7 mph N | 1% |
| Thursday Night | 62°F | Mostly Clear | 6 mph WNW | 1% |
| Friday | 98°F | Sunny | 1 to 7 mph SSE | 0% |
| Friday Night | 66°F | Mostly Clear | 3 to 7 mph SSW | 0% |
| Saturday | 100°F | Sunny | 2 to 7 mph N | 3% |
| Saturday Night | 67°F | Partly Cloudy | 6 mph WNW | 0% |
| Sunday | 99°F | Sunny | 6 mph N | 9% |
| Sunday Night | 68°F | Partly Cloudy | 6 mph WNW | 4% |
| Monday | 97°F | Mostly Sunny then Chance Showers And Thunderstorms | 5 to 8 mph NNW | 32% |
| Monday Night | 67°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 to 8 mph W | 18% |
Forecast source: National Weather Service (api.weather.gov) for Boulder (40.024, -105.251). Updated through the day.
Growing snapshot for Boulder
Last spring frost
May 6
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
6a
More local growing data for Boulder: nearby ZIP 80310 weather · frost dates · planting calendar · Colorado frost dates
Nearby towns & communities
Allenspark
Altona
Bark Ranch
Bonanza Mountain Estates
Coal Creek
Crisman
Eldorado Springs
Glendale
Gold Hill
Gunbarrel
Hidden Lake
Jamestown
Lafayette
Lazy Acres
Leyner
Longmont
Louisville
Lyons
Mountain Meadows
Nederland
Niwot
Paragon Estates
Pine Brook Hill
Seven Hills
St. Ann Highlands
Sugarloaf
Sunshine
Superior
Tall Timber
Valmont
Climate data from the nearest NOAA station, Boulder, Co (0.9 mi from Boulder). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.