Boulder (CO)
May
Weather in Boulder, Colorado for May 2026
Your guide to Boulder weather in May - trends and predictions
In general, the average temperature in Boulder at the beginning of May is 15.1 °F. As the month progressed, temperatures tended to significantly warm up, reaching an average of 19.6 °F by the end of May.
The climate of Boulder in May is notably wet, with an average of 15 rainy days, and a total of 41.9 mm of precipitation.
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Temperatures
Rain 🌧️
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16
Dry days
15
Rainy days
0
Snow days
18°/6°
Temperatures
22 km/h
Avg max wind
51 %
Avg humidity
Boulder Weather May
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Temperatures trend during May in Boulder
See the weather trend as well as the moving average line
May weather in Boulder day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| May 1 |  Moderate rain at times | 13° /3° | 2.1 mm | 3 | |
| May 2 |  Partly cloudy | 16° /1° | 0.2 mm | 5 | |
| May 3 |  Patchy rain possible | 19° /2° | 0.2 mm | 5 | |
| May 4 |  Overcast | 19° /6° | 0 mm | 5 | |
| May 5 | Overcast | 17° /4° | 17.4 mm | 4 | |
| May 6 | Patchy rain possible | 11° /3° | 51.6 mm | 3 | |
| May 7 | Patchy rain possible | 11° /1° | 26.6 mm | 3 | |
| May 8 |  Cloudy | 14° /2° | 0 mm | 4 | |
| May 9 | Overcast | 15° /4° | 1.2 mm | 4 | |
| May 10 | Moderate rain at times | 17° /4° | 0.9 mm | 5 | |
| May 11 | Patchy rain possible | 21° /7° | 0.3 mm | 6 | |
| May 12 | Moderate or heavy rain shower | 22° /9° | 4 mm | 6 | |
| May 13 | Patchy rain possible | 22° /10° | 0.1 mm | 5 | |
| May 14 | Overcast | 19° /7° | 0 mm | 5 | |
| May 15 | Moderate or heavy rain shower | 16° /7° | 1.6 mm | 4 | |
| May 16 | Cloudy | 20° /6° | 0 mm | 5 | |
| May 17 | Cloudy | 20° /9° | 0 mm | 5 | |
| May 18 | Overcast | 20° /9° | 0 mm | 5 | |
| May 19 | Cloudy | 19° /8° | 0 mm | 4 | |
| May 20 | Patchy rain possible | 20° /6° | 4.1 mm | 5 | |
| May 21 | Moderate or heavy rain shower | 17° /6° | 4.1 mm | 5 | |
| May 22 | Partly cloudy | 21° /4° | 0 mm | 6 | |
| May 23 | Cloudy | 26° /8° | 0.1 mm | 6 | |
| May 24 | Overcast | 16° /5° | 7.6 mm | 4 | |
| May 25 |  Heavy rain at times | 16° /6° | 35.5 mm | 4 | |
| May 26 |  Sunny | 15° /6° | 9.9 mm | 4 | |
| May 27 | Sunny | 20° /8° | 1.7 mm | 5 | |
| May 28 | Cloudy | 19° /8° | 0 mm | 5 | |
| May 29 | Cloudy | 21° /7° | 2.2 mm | 5 | |
| May 30 | Overcast | 23° /9° | 5.3 mm | 5 | |
| May 31 |  Patchy light drizzle | 23° /8° | 0.5 mm | 6 | |
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Important Notice
Our weather forecast for Boulder in May is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Boulder forecast closer to your planned date for the most up-to-date weather information.
Change Month
Boulder in May - FAQ
What are the expected maximum and minimum temperatures in Boulder during May?
Enjoy moderate daytime temperatures of up to 18° and cooler nights around 6°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Boulder during May?
In May, Boulder can expect light to moderate rainfall, totaling 41.9 mm across approximately 15 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Boulder during May?
The average wind speed in Boulder during May is 22 km/h, suggesting breezy to windy conditions, depending on your activities.
May rainfall patterns in Boulder
Explore the daily rainfall trends and prepare for Boulders May weather 💧
UV exposure in Boulder during May
Stay informed about UV levels for safe outdoor activities throughout the month of May ☀️
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