Average data for 10 years
1 September
Sunday
+22°
+15°
2 September
Monday
+21°
+14°
3 September
Tuesday
+21°
+13°
4 September
Wednesday
+20°
+14°
5 September
Thursday
+19°
+13°
6 September
Friday
+20°
+13°
7 September
Saturday
+20°
+12°
8 September
Sunday
+20°
+13°
9 September
Monday
+19°
+12°
10 September
Tuesday
+18°
+11°
11 September
Wednesday
+17°
+11°
12 September
today
+18°
+11°
13 September
tomorrow
+17°
+11°
14 September
Saturday
+16°
+10°
15 September
Sunday
+18°
+12°
16 September
Monday
+18°
+12°
17 September
Tuesday
+18°
+11°
18 September
Wednesday
+19°
+12°
19 September
Thursday
+19°
+11°
20 September
Friday
+18°
+12°
21 September
Saturday
+17°
+11°
22 September
Sunday
+16°
+9°
23 September
Monday
+17°
+11°
24 September
Tuesday
+17°
+11°
25 September
Wednesday
+18°
+12°
26 September
Thursday
+17°
+11°
27 September
Friday
+16°
+11°
28 September
Saturday
+16°
+10°
29 September
Sunday
+17°
+10°
30 September
Monday
+16°
+9°
Cities with similar weather in September
United Kingdom
London
Netherlands
Amsterdam
Belgium
Brussels
Germany
Nuremberg
Switzerland
Bern
September in Boulder is the sunniest month of the year. In September, the weather in Boulder is typically warm. Average daily high temperature in September is about 18 degrees above zero. On average, Boulder has 20 sunny, 7 partly cloudy, and 3 rainy days in September. The rains are usually light. September as well as June is considered the most comfortable time to visit Boulder.