Boulder, CO
Climate overview — based on NOAA 1991-2020 normals from BOULDER, CO US.
Year-round temperatures (°F)
Climate summary
Boulder has an annual average temperature of 51.5°F with about 21.2 inches of precipitation per year and 92.8 inches of snow. The warmest month is July (average high 88.0°F), and the coldest is December (average low 21.1°F). May is typically the wettest month (3.21 in) and December the driest (0.81 in). Snow typically falls from September through May.
Best time to visit Boulder
Full guide →Climate change signal
All-time records →71 of 366 (19.4%) of Boulder's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1890s | 2 | |
| 1900s | 16 | |
| 1910s | 12 | |
| 1920s | 15 | |
| 1930s | 23 | |
| 1940s | 24 | |
| 1950s | 44 | |
| 1960s | 20 | |
| 1970s | 12 | |
| 1980s | 43 | |
| 1990s | 25 | |
| 2000s | 42 | |
| 2010s | 39 | |
| 2020s | 49 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 47.0°F | 21.5°F | 34.3°F | 0.83 in | 11.3 in | 6 |
| February | 48.3°F | 22.3°F | 35.3°F | 0.99 in | 15.0 in | 7 |
| March | 57.0°F | 29.0°F | 43.0°F | 1.99 in | 15.7 in | 8 |
| April | 62.8°F | 34.5°F | 48.7°F | 3.05 in | 14.7 in | 10 |
| May | 71.3°F | 42.7°F | 57.0°F | 3.21 in | 2.0 in | 13 |
| June | 82.5°F | 51.1°F | 66.8°F | 1.95 in | — | 10 |
| July | 88.0°F | 57.0°F | 72.5°F | 1.83 in | — | 11 |
| August | 86.0°F | 55.5°F | 70.7°F | 1.68 in | — | 11 |
| September | 78.8°F | 48.1°F | 63.5°F | 2.09 in | 1.0 in | 8 |
| October | 65.9°F | 37.2°F | 51.6°F | 1.62 in | 7.0 in | 7 |
| November | 54.5°F | 28.1°F | 41.3°F | 1.18 in | 13.1 in | 6 |
| December | 46.3°F | 21.1°F | 33.7°F | 0.81 in | 13.0 in | 5 |
Climate twins of Boulder
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).