August Weather in Boulder

Last updated: March 2, 2024

The weather in Boulder, United States, during August is characterized by an average temperature of 19°C (67°F). Highs can soar to 31°C (88°F), while lows may dip to 9°C (48°F). Typically, the humidity level in Boulder throughout August hovers around 56%.

9°C (48°F)

Minimum temperature

19°C (67°F)

Average temperature

31°C (88°F)

Maximum temperature

56%

Humidity

Precipitation and Sunshine hours

In August, Boulder averages 67 mm (2.7 inches) of rainfall, typically over the course of 13 rainy days. The month enjoys an average of 13 hours 39 minutes of daylight, with the sun shining for approximately 11 hours 19 minutes each day. Additionally, there is a 65% probability of sunny days during this period.

67 mm (2.7 inches)

Precipitation

13 rainy days

Rainy days

11 hours 19 minutes

Sunshine hours

65%

Chance of sun

UV Index

In August, the UV Index in Boulder reaches a maximum of 11, indicating a level of Extreme exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 10 minutes.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
  07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00
UVI 1 2 3 6 8 10 11 10 8 6 3 2 1
Exposure Low Moderate High VeryHigh Extreme VeryHigh High Moderate Low
Time to burn 45 min 30 min 25 min 15 min 10 min 15 min 25 min 30 min 45 min

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