Longmont, CO All-Time Weather Extremes
The most extreme temperature, precipitation, and snowfall ever recorded in Longmont, from NOAA daily weather observations.
| Temperature | ||
|---|---|---|
| Record High | 105.9°F (41°C) | July 7, 1973 and June 27, 1994 |
| Record Low | -38°F (-39°C) | January 16, 1930 |
| Lowest High | -9.9°F (-23°C) | February 5, 1989 |
| Highest Low | 73.9°F (23°C) | July 3, 1999 |
| Highest Mean | 86.5°F (30°C) | July 30, 1980 |
| Lowest Mean | -20.5°F (-29°C) | January 12, 1963 |
| Precipitation | ||
| Max in One Calendar Day | 4.62" (117.3 mm) | May 30, 1896 |
| Max in One Month | 7.00" (177.8 mm) | May 1995 |
| Least in One Month | 0.00" (0.0 mm) | January 1919 |
| Max in One Year | 22.74" (577.5 mm) | 1915 |
| Least in One Year | 6.42" (163.0 mm) | 1939 |
| Snowfall | ||
| Max in One Calendar Day | 37.0" (94.0 cm) | April 18, 1920 |
| Max in One Month | 51.0" (129.6 cm) | April 1920 |
| Max in One Season | 83.5" (212.2 cm) | 1919-20 |
| Max in One Year | 76.2" (193.6 cm) | 1920 |
| Earliest Snow | 1.4" (3.6 cm) | September 9, 2020 |
| Earliest Measurable Snow | 1.4" (3.6 cm) | September 9, 2020 |
| Latest Snow | 1.0" (2.5 cm) | May 28, 1947 |
| Latest Measurable Snow | 1.0" (2.5 cm) | May 28, 1947 |
| Period of Record | ||
| Temperature | January 1, 1893 – August 3, 2026 | |
| Precipitation | January 1, 1893 – August 3, 2026 | |
| Snowfall | February 1, 1893 – August 3, 2026 | |
Note: Records compiled from NOAA GHCN-Daily observations at LONGMONT 2 ESE (1 mi from Longmont, 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 Longmont, CO?
The all-time record high in Longmont, CO is 105.9°F (41°C), set on July 7, 1973 and June 27, 1994.
What is the coldest temperature ever recorded in Longmont, CO?
The all-time record low in Longmont, CO is -38°F (-39°C), set on January 16, 1930.
What is the most rain Longmont, CO has ever had in one day?
The most precipitation recorded in one calendar day near Longmont, CO is 4.62 inches, on May 30, 1896.
What is the biggest snowfall ever recorded in Longmont, CO?
The most snow recorded in one calendar day near Longmont, CO is 37.0 inches, on April 18, 1920.
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Longmont Weather History
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