Longmont (CO) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Longmont.
Climate overview of Longmont
The climate in Longmont, Colorado, United States of America, is marked by large temperature swings across the seasons, ranging from 32°C (90°F) in July to 6°C (43°F) in December.
The city has a relatively dry climate, receiving around 363 mm (14 in) of rain/snowfall per year. It does experience a distinct dry season from June to March. May is the wettest month and January the driest. Sunshine peaks in July, when the city sees around 10.8 hours of sunshine per day.
Longmont Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Longmont — and find the best time to visit.
Monthly Temperature in Longmont
In Longmont, temperatures differ significantly between summer and winter months. On average, daytime temperatures range from a very warm 32°C (90°F) in July to a chilly 6°C (43°F) in December.
Nighttime temperatures range from 14°C (57°F) in July to -10°C (14°F) in December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Longmont
Longmont's climate is marked by below-average rain/snowfall, accumulating 363 mm (14 in) of precipitation yearly. The seasons in Longmont bring significant changes in precipitation. The wettest month, May, receives moderate rainfall, with an average of 62 mm (2.4 in) of precipitation. This rainfall is distributed across 12 rainy days.
In contrast, the driest month, January, experiences much less snow/rainfall, totaling 9.5 mm (0.4 in) over 4 snowy/rainy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Longmont Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Longmont
In Longmont, summer days are longer and more sunny, with daily sunshine hours peaking at 10.8 hours in July. As the darker season arrives, the brightness of the sun becomes less. November sees a soft sun for only 6.5 hours per average day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Longmont by Month
The relative humidity is moderate throughout the year in Longmont.
The city experiences its highest humidity in December, reaching 56%. In July, the humidity drops to its lowest level at 46%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Longmont
Frequently asked questions about the climate in Longmont
What is the best time to visit Longmont?
May and September typically offer the most optimal weather in Longmont. In contrast, January, February and December tend to have less optimal conditions. Longmont has a distinct dry season from June to March.
What temperatures can I expect in Longmont?
Daytime highs range from 6°C (43°F) in December to 32°C (90°F) in July. Nighttime lows range from -10°C (14°F) to 14°C (57°F). Temperatures vary considerably through the year.
How much rain does Longmont get?
Annual rainfall is around 363 mm (14 in). May is the wettest month with 62 mm (2.4 in), while January is the driest with 9.5 mm (0.4 in).
How sunny is Longmont?
Longmont receives around 3,102 hours of sunshine per year. July is the sunniest month with 323 hours, while November is the cloudiest with just 195 hours. Overall, Longmont enjoys abundant sunshine.
Longmont 3-Day Forecast
Longmont (CO) 3-Day Forecast
Longmont on the map
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