Historical Weather in Thornton, CO
See 55+ years of weather history for any date in Thornton going back to 1970.
Part of Colorado weather history
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Today in Thornton Weather HistorySee records, averages, and 55+ years of data for today's date
→Monthly Climate Averages
Historical temperature and precipitation averages for Thornton, CO, based on 55+ years of weather data.
Warmest MonthJulyAvg High: 90°F / Low: 58°F
Coldest MonthJanuaryAvg High: 45°F / Low: 17°F
Jan
45°/ 17°
💧 2.5"
❄️ 1.4"
Feb
47°/ 19°
💧 2.7"
❄️ 1.5"
Mar
56°/ 27°
💧 4.7"
❄️ 1.9"
Apr
63°/ 34°
💧 5.7"
❄️ 1.9"
May
71°/ 43°
💧 6.3"
❄️ 2.0"
Jun
84°/ 53°
💧 5.5"
Jul
90°/ 58°
💧 5.5"
Aug
87°/ 57°
💧 4.8"
Sep
80°/ 48°
💧 5.2"
❄️ 2.0"
Oct
67°/ 36°
💧 4.6"
❄️ 2.1"
Nov
54°/ 26°
💧 3.8"
❄️ 1.8"
Dec
46°/ 18°
💧 3.0"
❄️ 1.6"
Temperatures in Fahrenheit. Precipitation and snowfall in inches.
Thornton Temperature Records
- Record High: The hottest temperature ever recorded in Thornton, CO is 110°F, set on August 2, 2008.
- Record Low: The coldest temperature ever recorded in Thornton, CO is -26°F, set on December 22, 1990.
- Data Coverage: Based on 43 years of data from NOAA weather station: NORTHGLENN.
All-Time Record High
110°F
August 2, 2008
All-Time Record Low
-26°F
December 22, 1990
Monthly Temperature Records in Thornton
| Month | Record High | Record Low |
|---|---|---|
| January | 78°F(1982) | -23°F(2024) |
| February | 83°F(2017) | -24°F(1989) |
| March | 85°F(2017) | -13°F(2002) |
| April | 92°F(1992) | -8°F(1975) |
| May | 101°F(2003) | 19°F(2010) |
| June | 107°F(2012) | 33°F(1998) |
| July | 108°F(2005) | 40°F(1987) |
| August | 110°F(2008) | 37°F(1992) |
| September | 102°F(2020) | 14°F(1985) |
| October | 94°F(1991) | 0°F(1997) |
| November | 85°F(2025) | -14°F(1993) |
| December | 82°F(2025) | -26°F(1990) |
Thornton Snow RecordsSee the top 10 snowiest days ever recorded
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