Niwot, CO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Niwot, a community in Boulder County, Colorado.
This Afternoon
83°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly cloudy. High near 83, with temperatures falling to around 74 in the afternoon. 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 Niwot
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 83°F | Chance Showers And Thunderstorms | 6 mph SW | 45% |
| Tonight | 52°F | Chance Showers And Thunderstorms then Partly Cloudy | 2 to 6 mph W | 28% |
| Saturday | 76°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 1 to 6 mph WSW | 65% |
| Saturday Night | 48°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 3 mph WNW | 48% |
| Sunday | 71°F | Chance Rain Showers | 3 mph NE | 54% |
| Sunday Night | 47°F | Chance Rain Showers then Partly Cloudy | 0 to 3 mph NW | 32% |
| Monday | 73°F | Sunny | 0 to 5 mph ENE | 3% |
| Monday Night | 48°F | Mostly Clear | 0 to 3 mph NNW | 9% |
| Tuesday | 76°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 0 to 3 mph NE | 16% |
| Tuesday Night | 50°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph NW | 19% |
| Wednesday | 78°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 1 to 5 mph NE | 16% |
| Wednesday Night | 50°F | Slight Chance Rain Showers then Mostly Cloudy | 2 mph SSW | 17% |
| Thursday | 78°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 1 to 5 mph NNE | 15% |
| Thursday Night | 51°F | Chance Rain Showers then Mostly Cloudy | 0 to 3 mph SW | 26% |
Forecast source: National Weather Service (api.weather.gov) for Niwot (40.098, -105.158). Updated through the day.
Growing snapshot for Niwot
Last spring frost
May 7
First fall frost
Oct 5
Growing season
151 days
More local growing data for Niwot: nearby ZIP 80544 weather · frost dates · planting calendar · Colorado frost dates
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Climate data from the nearest NOAA station, Longmont 2 Ese, Co (6.8 mi from Niwot). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.