September Weather in Grand Junction

Last updated: March 2, 2024

The weather in Grand Junction, United States, during September is characterized by an average temperature of 19°C (66°F). Highs can soar to 34°C (93°F), while lows may dip to 3°C (38°F). Typically, the humidity level in Grand Junction throughout September hovers around 53%.

3°C (38°F)

Minimum temperature

19°C (66°F)

Average temperature

34°C (93°F)

Maximum temperature

53%

Humidity

Precipitation and Sunshine hours

In September, Grand Junction averages 40 mm (1.6 inches) of rainfall, typically over the course of 6 rainy days. The month enjoys an average of 12 hours 23 minutes of daylight, with the sun shining for approximately 10 hours 30 minutes each day. Additionally, there is a 75% probability of sunny days during this period.

40 mm (1.6 inches)

Precipitation

6 rainy days

Rainy days

10 hours 30 minutes

Sunshine hours

75%

Chance of sun

UV Index

In September, the UV Index in Grand Junction reaches a maximum of 10, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 15 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 1 2 5 7 9 10 9 7 5 3 1 1
Exposure Low Moderate High VeryHigh High Moderate Low
Time to burn 45 min 30 min 25 min 15 min 25 min 30 min 45 min

Compare Grand Junction's Climate with Cities Worldwide