Thornton, CO All-Time Weather Extremes
The most extreme temperature, precipitation, and snowfall ever recorded in Thornton, from NOAA daily weather observations.
| Temperature | ||
|---|---|---|
| Record High | 104°F (40°C) | June 26, 1994 and July 21, 2005 and June 26, 2012 |
| Record Low | -25°F (-32°C) | December 22, 1990 |
| Lowest High | -9°F (-23°C) | February 4, 1989 |
| Highest Low | 71.9°F (22°C) | July 25, 2003 |
| Highest Mean | 87.0°F (31°C) | June 27, 2012 |
| Lowest Mean | -14.4°F (-26°C) | December 21, 1983 |
| Precipitation | ||
| Max in One Calendar Day | 3.88" (98.6 mm) | September 12, 2013 |
| Max in One Month | 7.42" (188.5 mm) | September 2013 |
| Least in One Month | 0.00" (0.0 mm) | March 2012 |
| Max in One Year | 24.12" (612.6 mm) | 2015 |
| Least in One Year | 8.52" (216.3 mm) | 2002 |
| Snowfall | ||
| Max in One Calendar Day | 23.6" (59.9 cm) | December 24, 1982 |
| Max in One Month | 35.2" (89.5 cm) | March 2003 |
| Max in One Season | 95.1" (241.5 cm) | 1972-73 |
| Max in One Year | 98.5" (250.3 cm) | 1973 |
| Earliest Snow | 1.3" (3.3 cm) | September 9, 2020 |
| Earliest Measurable Snow | 1.3" (3.3 cm) | September 9, 2020 |
| Latest Snow | 5.6" (14.2 cm) | May 29, 1975 |
| Latest Measurable Snow | 5.6" (14.2 cm) | May 29, 1975 |
| Period of Record | ||
| Temperature | January 1, 1970 – June 30, 2026 | |
| Precipitation | January 1, 1970 – June 28, 2026 | |
| Snowfall | January 1, 1970 – June 28, 2026 | |
Note: Records compiled from NOAA GHCN-Daily observations at DENVER-STAPLETON (8 mi from Thornton, CO). Quality-flagged readings are excluded. Monthly and annual totals require substantially complete reporting for “least” records.
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Frequently Asked Questions
What is the hottest temperature ever recorded in Thornton, CO?
The all-time record high in Thornton, CO is 104°F (40°C), set on June 26, 1994 and July 21, 2005 and June 26, 2012.
What is the coldest temperature ever recorded in Thornton, CO?
The all-time record low in Thornton, CO is -25°F (-32°C), set on December 22, 1990.
What is the most rain Thornton, CO has ever had in one day?
The most precipitation recorded in one calendar day near Thornton, CO is 3.88 inches, on September 12, 2013.
What is the biggest snowfall ever recorded in Thornton, CO?
The most snow recorded in one calendar day near Thornton, CO is 23.6 inches, on December 24, 1982.
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Thornton Weather History
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