Measurements:
°C
°F
CURRENT WEATHER
16:21
Boulder
30°F
E 15 mph
Feels like: 20°F
Precip: 0%
World Resorts USA Boulder Weather September Weather in Boulder

Boulder Weather: September

Average Day Temperature: 70.8°F
Average Night Temperature: 50.2°F
Number of Sunny Days: 21 days
Sunshine Hours: 11.8 - 13.1 hours
Number of Rainy Days: 1 day
Precipitation Totals: 0.7 in
detailed information

Air Temperature in September, °F

Select Year: 2024 2023 2022
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
0
15
30
45
60
75
90
105
120
Day Temperature   
Night Temperature

The highest day temperature in September 2024 was 93°F. The lowest night temperature was 46°F. The average values for day and night temperatures during September were 79.6°F и 59.3°F respectivly.

Sunny, Cloudy and Gloomy days
Sunny days
Cloudy days
Gloomy days
68%
23%
10%

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation Totals in September, in

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
0.0
0.4
0.8
1.3
1.7
2.1
2.5
2.9
3.4

Precipitation total in September for Boulder is 0.7 in.

Wind Speed in September, mph
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
0.0
1.5
3.0
4.5
6.0
7.5
9.0
10.5

The average wind speed in September is 6.6 mph. This value is relatively stable throughout the year.

Average Sunny Hours Per Day
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
0.0
1.7
3.3
5.0
6.7
8.3
10.0
11.6

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Boulder in September is 9.6 hours.

Best Time to Visit Boulder
The most sunny months:
September 21 days
October 21 days
November 19 days
The most warm months:
July 76.7 °F
August 75.6 °F
September 70.8 °F
The most cold months:
January 27.8 °F
February 30.0 °F
March 35.5 °F
The most rainy months:
June 6 days
July 5 days
May 4 days
The most windy months:
December 9 mph
February 8 mph
January 8 mph
more details

Boulder on the Weather Map

USA Resorts:
NAME
F°
Boston +46
Chicago +60
Hawaii +78
Honolulu +78
Houston +82
Las Vegas +66
Los Angeles +66
Miami +82
New York +44
Orlando +88
San Diego +60
San Francisco +52
Sarasota +86
Tampa +88
Washington +52
all resorts
24 Hours Weather Forecast
Boulder
Local time: 16:21
15 mar, saturday
1800 30°F
SE
15 mph
2100 22°F
E
9 mph
16 mar, sunday
0000 20°F
E
8 mph
0300 18°F
E
19 mph
0600 18°F
E
21 mph
0900 22°F
E
16 mph
1200 34°F
E
15 mph
1500 42°F
E
21 mph