Boulder, CO Weather & Climate Normals
What a normal year in Boulder actually looks like
On the 30-year record NOAA keeps for Boulder, CO, the comfort score comes out to 42/100, strongly seasonal: Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. Only 5 months a year land in the 55–75°F range this site treats as mild.
How much Boulder's weather actually swings
Average temperatures in Boulder run from 34°F in Dec up to 73°F in Jul, a 38.8°F seasonal swing, a middling gap by national standards.
Boulder, month by month
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 47°F | 22°F | 0.83in | 11.3in |
| Feb | 48°F | 22°F | 0.99in | 15in |
| Mar | 57°F | 29°F | 1.99in | 15.7in |
| Apr | 63°F | 35°F | 3.05in | 14.7in |
| May | 71°F | 43°F | 3.21in | 2in |
| Jun | 83°F | 51°F | 1.95in | 0in |
| Jul | 88°F | 57°F | 1.83in | 0in |
| Aug | 86°F | 56°F | 1.68in | 0in |
| Sep | 79°F | 48°F | 2.09in | 1in |
| Oct | 66°F | 37°F | 1.62in | 7in |
| Nov | 55°F | 28°F | 1.18in | 13.1in |
| Dec | 46°F | 21°F | 0.81in | 13in |
If you're timing a visit, May, Jun, Jul, Aug, and Sep are Boulder's mildest stretch; if you're moving there, you should plan around Dec's cold instead.
How wet Boulder actually gets
Over a typical year, Boulder sees about 21.23in of precipitation a year across roughly 101 days with measurable rain or snow, with 92.8in of snow a year.
Boulder against the rest of the country
Out of 4876 cities scored here, Boulder comes in at 4159; within CO alone it ranks 55 of 79. Population is about 106,803.
Checking the actual forecast
These figures come from Boulder, CO US, the NOAA station 2.4 miles from Boulder, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why this uses the nearest NOAA station · How the comfort score is calculated