Harman US

Niwot, CO Weather & Growing Conditions

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

WhenTempForecastWindPrecip
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). Updated through the day.

Growing snapshot for Niwot, CO

Last spring frost
May 7
First fall frost
Oct 5
Growing season
151 days

Explore more for Niwot, CO: full frost dates · planting calendar · Colorado frost dates

Climate data from the nearest NOAA station, Longmont 2 Ese, Co (6.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.