Yosemite National Park is definitely worth a visit
Vast forests, blue lakes, towering sequoias, and majestic waterfalls hint at the beauty of Yosemite National Park—a true natural masterpiece.
Boulder Weather in September
September in Boulder typically sees daytime highs of 26°C (79°F) and nighttime lows of 10°C (50°F). Rainfall is also possible this month, so it's worth packing an umbrella.
Rainfall in Boulder in September
Typically, you can expect about 8 days of rain this month, with 67 mm (2.6 in) on average. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.
Temperature in Boulder in September
Boulder in September is worth a visit. The temperature is excellent, with 26°C (79°F) during the day and 10°C (50°F) at night. Conditions stay fairly consistent through the month, making it easier to plan what to wear. With lows around 10°C (50°F), nights are cold. The upside is that cool, crisp nights are often the best for a deep sleep.
Sunshine in Boulder in September
Expect sunny days throughout the month, with an estimated 270 hours of sunshine. This makes it a pleasant time to visit Boulder.If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.
Boulder Temperature in September
Min Temperature
10°C (50°F)
Max Temperature
26°C (79°F)
Chance of Rain
27%
Precipitation
67 mm (2.6 in)
Rainy days
8 days
Humidity
50% *
Sunshine
270 hours *
Percentage Sunshine
73% *
* Data from: Denver, the United States of America (45 KM, 28 Miles).
Boulder Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Boulder - and find the best time to visit.
Best Places in the United States of America in September
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in September →
perfect weather
pleasant
tolerable
unpleasant
poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).
What to Wear in Boulder in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Rain is likely on several days, so bring a good rain jacket. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.
What To Do in Boulder in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
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Swimming9/10 -
Cycling8/10 -
Walking8/10 -
Camping4/10 -
Outdoor sports8/10
Boulder 3-Day Forecast
More climate data for Boulder
Temperature Rainfall Sunshine Humidity
See the full Boulder climate overview or explore weather in the United States of America.
Popular in September
Where to go in September - average daytime high across popular destinations.
Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
Yosemite National Park is definitely worth a visit
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