Boulder, CO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Boulder, a city in Boulder County, Colorado.
This Afternoon
81°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly cloudy. High near 81, with temperatures falling to around 71 in the afternoon. South southwest wind around 6 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Boulder
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 81°F | Chance Showers And Thunderstorms | 6 mph SSW | 49% |
| Tonight | 54°F | Chance Showers And Thunderstorms then Partly Cloudy | 2 to 6 mph W | 26% |
| Saturday | 76°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 1 to 6 mph WNW | 66% |
| Saturday Night | 49°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 0 to 3 mph W | 47% |
| Sunday | 71°F | Chance Showers And Thunderstorms | 0 to 3 mph NNE | 45% |
| Sunday Night | 48°F | Chance Rain Showers then Partly Cloudy | 0 to 3 mph NNW | 33% |
| Monday | 73°F | Sunny | 0 to 5 mph ENE | 4% |
| Monday Night | 50°F | Mostly Clear | 0 to 3 mph N | 7% |
| Tuesday | 76°F | Mostly Sunny then Chance Showers And Thunderstorms | 0 to 3 mph ENE | 25% |
| Tuesday Night | 52°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 3 mph NNW | 20% |
| Wednesday | 77°F | Partly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph NE | 25% |
| Wednesday Night | 52°F | Slight Chance Rain Showers then Mostly Cloudy | 2 mph SSW | 19% |
| Thursday | 77°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 1 to 5 mph NE | 18% |
| Thursday Night | 53°F | Chance Rain Showers then Mostly Cloudy | 0 to 3 mph WSW | 27% |
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
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Bonanza Mountain Estates
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Crisman
Eldorado Springs
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Gunbarrel
Hidden Lake
Jamestown
Lafayette
Lazy Acres
Leyner
Longmont
Louisville
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Mountain Meadows
Nederland
Niwot
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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 Sep 18, 2026.