Thornton, CO Weather & Growing Conditions
Today
79°F
Partly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after noon. Partly sunny. High near 79, with temperatures falling to around 71 in the afternoon. Northeast wind 3 to 8 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 79°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 8 mph NE | 52% |
| Tonight | 52°F | Chance Showers And Thunderstorms then Partly Cloudy | 2 to 8 mph SW | 37% |
| Sunday | 70°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 2 to 8 mph N | 32% |
| Sunday Night | 51°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 1 to 8 mph NNE | 22% |
| Monday | 73°F | Sunny | 1 to 8 mph NE | 2% |
| Monday Night | 52°F | Partly Cloudy | 2 to 8 mph NNW | 6% |
| Tuesday | 78°F | Mostly Sunny | 2 to 7 mph NNE | 4% |
| Tuesday Night | 54°F | Partly Cloudy | 6 mph SW | 14% |
| Wednesday | 78°F | Mostly Sunny | 6 mph NNE | 8% |
| Wednesday Night | 54°F | Mostly Cloudy | 2 to 6 mph SW | 11% |
| Thursday | 79°F | Mostly Sunny | 2 to 8 mph S | 6% |
| Thursday Night | 56°F | Partly Cloudy | 2 to 8 mph S | 13% |
| Friday | 80°F | Mostly Sunny | 2 to 7 mph S | 11% |
| Friday Night | 56°F | Slight Chance Rain Showers then Partly Cloudy | 3 to 7 mph S | 15% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Thornton, CO
Last spring frost
May 2
First fall frost
Oct 11
Growing season
160 days
Hardiness zone
6a
Explore more for Thornton, CO: full frost dates · planting calendar · Colorado frost dates
Climate data from the nearest NOAA station, Northglenn, Co (3.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.