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September Weather in Petersburg, United States

Last updated: June 24, 2025

In September, the average temperature in Petersburg, United States is a warm 23°C (75°F), with fluctuations ranging from a chilly 9°C (49°F) to a sizzling 36°C (97°F). Expect about 109 mm (4.3 in) of precipitation over approximately 9 days, and a comfortable average humidity of 64%. Embrace the diverse weather this month brings!

September Temperature in Petersburg

In September in Petersburg, the average temperature is 23°C (75°F). Maximums can reach 36°C (97°F) and minimums can be as low as 9°C (49°F). This range makes it an ideal destination for travelers looking for moderate weather and a chance to experience both warm days and cooler evenings.

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 23°C (75°F), with highs reaching up to 36°C (97°F) and lows dropping to around 9°C (49°F).
JanFebMarAprMayJunJulAugSepOctNovDec424754607077807874644946
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 109 mm (4.3 in) spread over 9 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 109 mm (4.3 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec11418218515211013414211510911471144
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 64%. With an average temperature of 23°C (75°F), this humidity feels like a warm, tropical embrace, making travel somewhat sticky but also invigorating, as the air wraps around you, enriching every breath with a hint of that seasonal atmosphere.

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 64%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%87%85%82%83%82%78%67%64%75%87%89%
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 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check 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 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec46810101111109753
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 Weather6°C (42°F)114 mm (4.5 inches)87%moderate
February Weather8°C (47°F)182 mm (7.2 inches)87%high
March Weather12°C (54°F)185 mm (7.3 inches)85%very high
April Weather16°C (60°F)152 mm (6.0 inches)82%very high
May Weather21°C (71°F)110 mm (4.3 inches)83%very high
June Weather25°C (77°F)134 mm (5.3 inches)82%extreme
July Weather26°C (80°F)142 mm (5.6 inches)78%extreme
August Weather26°C (79°F)115 mm (4.5 inches)67%very high
September Weather23°C (75°F)109 mm (4.3 inches)64%very high
October Weather18°C (64°F)114 mm (4.5 inches)74%high
November Weather10°C (50°F)71 mm (2.8 inches)87%moderate
December Weather8°C (47°F)144 mm (5.7 inches)88%moderate

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