September Weather in Mount Vernon

Last updated: March 2, 2024

The weather in Mount Vernon, United States, during September is characterized by an average temperature of 15°C (59°F). Highs can soar to 26°C (78°F), while lows may dip to 7°C (45°F). Typically, the humidity level in Mount Vernon throughout September hovers around 76%.

7°C (45°F)

Minimum temperature

15°C (59°F)

Average temperature

26°C (78°F)

Maximum temperature

76%

Humidity

Precipitation and Sunshine hours

In September, Mount Vernon averages 146 mm (5.8 inches) of rainfall, typically over the course of 12 rainy days. The month enjoys an average of 12 hours 30 minutes of daylight, with the sun shining for approximately 8 hours 47 minutes each day. Additionally, there is a 31% probability of sunny days during this period.

146 mm (5.8 inches)

Precipitation

12 rainy days

Rainy days

8 hours 47 minutes

Sunshine hours

31%

Chance of sun

UV Index

In September, the UV Index in Mount Vernon reaches a maximum of 7, indicating a level of High exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 25 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 3 5 6 7 6 5 4 2 1 1
Exposure Low Moderate High Moderate Low
Time to burn 45 min 30 min 25 min 30 min 45 min

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