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Hourly Forecast
Daylight Hours
06:47
Sunrise
19:04
Sunset
Moon
Waxing Crescent
10:34
Moonrise
20:12
Moonset
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Weather in Boulder tomorrow, September 15, 2026
Boulder looks cloudy on September 15, 2026, with grey skies for much of the day. Sunshine stays limited, so the overall tone is muted from the morning onward. The morning sky stays heavily clouded, with cover near 100% around 00:00. Grey conditions set the early tone before any later change.
Temperatures climb from an overnight low near 13°C toward a daytime high of about 23°C. The air stays humid, with relative humidity between 20% and 57% and the peak around 09:00. Airflow remains manageable, reaching about 5.4 km/h around 01:00.
The afternoon keeps an overcast feel, as cloud reaches about 68% around 16:00. Outdoor plans may still want a flexible backup. Horizontal visibility holds close to 16.1 km. The sun rises at 06:48 and sets at 19:03, for a total of 12 hours 14 minutes of sunlight today.
Taken together, overcast skies in Boulder on September 15, 2026 favour indoor or covered options, with temperatures near 23°C.
Frequently asked questions about weather in Boulder
How warm does it get in Boulder?
The warmest month in Boulder is July, with average high temperatures of 28°C. The average temperature during this period is around 20°C.
How cold does it get in Boulder?
The coldest month in Boulder is January, with average low temperatures of -9°C. The average temperature during this period is around -4°C.
What is the wettest time of year in Boulder?
The wettest month in Boulder is May, with an average of 125mm of precipitation.
What is the driest time of year in Boulder?
The driest month in Boulder is December, with an average of 25mm of precipitation.
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