Thornton, CO Weather & Growing Conditions
Today
76°F
Mostly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms between noon and 3pm, then showers and thunderstorms likely. Mostly sunny. High near 76, with temperatures falling to around 70 in the afternoon. North northeast wind 2 to 9 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 76°F | Mostly Sunny then Chance Showers And Thunderstorms | 2 to 9 mph NNE | 59% |
| Tonight | 53°F | Chance Showers And Thunderstorms then Partly Cloudy | 2 to 7 mph WNW | 40% |
| Sunday | 71°F | Mostly Sunny then Chance Showers And Thunderstorms | 2 to 8 mph NNE | 29% |
| Sunday Night | 52°F | Chance Showers And Thunderstorms then Partly Cloudy | 1 to 7 mph N | 30% |
| Monday | 73°F | Sunny | 1 to 8 mph NE | 2% |
| Monday Night | 52°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 2 to 8 mph S | 20% |
| Tuesday | 76°F | Mostly Sunny | 2 to 6 mph ESE | 9% |
| Tuesday Night | 55°F | Partly Cloudy | 2 to 6 mph SSW | 14% |
| Wednesday | 78°F | Mostly Sunny | 2 to 6 mph NNE | 10% |
| Wednesday Night | 55°F | Mostly Cloudy | 2 to 6 mph WSW | 10% |
| Thursday | 79°F | Mostly Sunny | 2 to 7 mph S | 7% |
| Thursday Night | 57°F | Mostly Cloudy | 2 to 7 mph S | 13% |
| Friday | 80°F | Mostly Sunny | 2 to 7 mph S | 12% |
| Friday Night | 57°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 (2.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.