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September Weather in Petersburg, United States

Last updated: June 24, 2025

In Petersburg, United States, the average temperature in September hovers around 19°C (67°F). Expect a minimum temperature of 3°C (37°F) and a maximum that can soar to 34°C (94°F). During this time, the region experiences an average precipitation amount of 59 mm (2.3 in) spread over 8 days, with humidity levels reaching an average of 78%.

September Temperature in Petersburg

In September in Petersburg, the average temperature is 19°C (67°F). Maximums can reach 34°C (94°F), while minimums can be as low as 3°C (37°F). Pack accordingly to enjoy the varied climate during your travels!

September Weather in Petersburg: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Petersburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Petersburg, September typically has an average temperature of 19°C (67°F), with highs reaching up to 34°C (94°F) and lows dropping to around 3°C (37°F).
JanFebMarAprMayJunJulAugSepOctNovDec272838486071757367554033
Data source: Temperature data for Petersburg generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Petersburg

In Petersburg in September, the total precipitation amount is 59 mm (2.3 in) spread over 8 days.

September Precipitation Trends in Petersburg

The chart displays monthly precipitation patterns in Petersburg, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Petersburg, September typically receives around 59 mm (2.3 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec65677789126861057359998254
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Petersburg

In Petersburg in September humidity is 78%. With an average temperature of 19°C (67°F), this humidity feels like a warm, heavy blanket enveloping you, making traveling feel both sticky and sluggish as you navigate through the day.

September Average Humidity in Petersburg

This chart illustrates the average monthly humidity levels in Petersburg, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Petersburg is approximately 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%87%88%81%82%81%78%78%82%89%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Petersburg

In Petersburg in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Petersburg.

Maximum UV Index Levels in Petersburg for September

The chart shows the monthly maximum UV Index (UVI) for Petersburg in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Petersburg typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec25599101098642
Data source: Petersburg September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Petersburg Compares to Other Months

Weather in Petersburg varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Petersburg, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Petersburg, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (28°F)65 mm (2.6 inches)88%low
February Weather-2°C (29°F)67 mm (2.6 inches)87%moderate
March Weather3°C (38°F)77 mm (3.0 inches)87%moderate
April Weather9°C (48°F)89 mm (3.5 inches)87%very high
May Weather16°C (60°F)126 mm (5.0 inches)81%very high
June Weather21°C (71°F)86 mm (3.4 inches)82%very high
July Weather24°C (75°F)105 mm (4.1 inches)81%very high
August Weather23°C (73°F)73 mm (2.9 inches)78%very high
September Weather19°C (67°F)59 mm (2.3 inches)78%very high
October Weather13°C (55°F)99 mm (3.9 inches)82%high
November Weather4°C (40°F)82 mm (3.2 inches)89%moderate
December Weather1°C (33°F)54 mm (2.1 inches)86%low

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