World Resorts USA Boulder Weather

Boulder weather in May

Weather in Boulder: May

Average day temperature: 55.9°F
Average night temperature: 39.4°F
Number of sunny days: 10 days
Day length: 13.9 - 14.8 hours
Number of rainy days: 4 days
Precipitation totals: 2.5 in.

Air temperature in May, °F

Show year:
2025
2024
2023

The highest day temperature during May of 2025 was 72°F. At the same time the lowest night temperature was 30°F. Daily and nightly averages during May were 56.5°F and 40.7°F.

Sunny, partly cloudy and cloudy days

Mostly all days in May are partly cloudy but sunny or cloudy days are also possible.

Precipitation total in May, in.

Precipitation total value in Boulder in May is 2.5 in. Other months of the year show relatively similar values.

Wind speed in May, mph

The average wind speed value in May is 6.8 mph It makes May one of the least windy months of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in May is: 8.1.

Best time for vacation in Boulder

Sunniest months:
October 20 days
September 20 days
November 19 days
Warmest months:
July 75.7 °F
August 74.6 °F
June 69.7 °F
Coldest months:
January 30.0 °F
February 32.0 °F
December 37.0 °F
Rainiest months:
June 6 days
July 4 days
May 4 days
Windiest months:
December 8.7 mph
February 8.4 mph
January 8.3 mph

Boulder on a weather map

Boulder
+32°F
E 9 mph
Feels like: +21°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+75°F
+75°F
+45°F
+55°F
+70°F
+77°F
+70°F
+23°F
+57°F
+48°F
+63°F
+63°F
+46°F
+5°F
24 Hours Forecast
Boulder
Local time: 22:56
December 05, friday
0000
32°F
E
9 mph
0300
32°F
E
9 mph
0600
32°F
E
12 mph
0900
32°F
E
11 mph
1200
39°F
SW
4 mph
1500
41°F
SW
6 mph
1800
36°F
NE
6 mph
2100
34°F
E
5 mph
Units of measurement: °C / °F