Jamestown, CO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jamestown, a town in Boulder County, Colorado.
Tonight
32°F
Mostly Clear
Mostly clear, with a low around 32. West southwest wind around 3 mph.
7-day forecast for Jamestown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 32°F | Mostly Clear | 3 mph WSW | 1% |
| Wednesday | 47°F | Partly Sunny then Slight Chance Rain And Snow Showers | 1 to 6 mph NE | 17% |
| Wednesday Night | 31°F | Slight Chance Rain And Snow Showers then Mostly Cloudy | 3 mph NW | 18% |
| Thursday | 53°F | Sunny | 1 to 7 mph SSE | 0% |
| Thursday Night | 34°F | Partly Cloudy | 3 mph WSW | 1% |
| Friday | 51°F | Mostly Sunny then Slight Chance Rain And Snow Showers | 1 to 5 mph SSE | 16% |
| Friday Night | 32°F | Slight Chance Rain And Snow Showers then Partly Cloudy | 2 to 8 mph W | 16% |
| Saturday | 54°F | Sunny | 0 to 10 mph NNE | 2% |
| Saturday Night | 33°F | Mostly Clear | 1 to 7 mph W | 1% |
| Sunday | 61°F | Sunny | 0 to 10 mph W | 0% |
| Sunday Night | 41°F | Mostly Clear | 6 to 10 mph W | 0% |
| Monday | 60°F | Mostly Sunny | 1 to 12 mph NW | 0% |
| Monday Night | 39°F | Partly Cloudy | 1 to 7 mph W | 0% |
| Tuesday | 58°F | Mostly Sunny | 1 to 7 mph W | 7% |
Forecast source: National Weather Service (api.weather.gov) for Jamestown (40.123, -105.393). Updated through the day.
Growing snapshot for Jamestown
Last spring frost
Jun 21
First fall frost
Sep 2
Growing season
71 days
Hardiness zone
5b
More local growing data for Jamestown: nearby ZIP 80455 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
Glendale
Gold Hill
Gunbarrel
Hidden Lake
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 14 W, Co (8.6 mi from Jamestown). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.