nomadseason

September Weather in Petersburg, United States

Last updated: June 24, 2025

In Petersburg, United States, the average temperature in September is a pleasant 23°C (74°F). Expect temperature fluctuations, with a minimum of 4°C (40°F) and a maximum soaring to 37°C (98°F). During this month, be prepared for 57 mm (2.3 in) of precipitation spread over approximately 5 days, resulting in an average humidity of 69%. Enjoy the dynamic climate!

September Temperature in Petersburg

In September in Petersburg, the average temperature is 23°C (74°F), with maximums reaching 37°C (98°F) and minimums dropping to as low as 4°C (40°F). Travelers should be prepared for both warm days and cooler nights during this time.

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 (74°F), with highs reaching up to 37°C (98°F) and lows dropping to around 4°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec404354607078818073615044
Data source: Temperature data for Petersburg generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
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 57 mm (2.3 in) accumulated over 5 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 57 mm (2.3 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec181348366855303558461619
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Petersburg

In Petersburg in September humidity is 69%. With an average temperature of 23°C (74°F), this humidity feels like a warm embrace, making outdoor adventures enjoyable yet slightly sticky, perfect for leisurely strolls or exploring local attractions while staying hydrated.

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 69%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec75%74%66%70%75%79%78%71%69%70%82%82%
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 reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more 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 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec579111112121210864
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 Weather5°C (41°F)18 mm (0.7 inches)75%moderate
February Weather6°C (43°F)13 mm (0.5 inches)74%high
March Weather12°C (54°F)48 mm (1.9 inches)66%very high
April Weather16°C (60°F)36 mm (1.4 inches)70%extreme
May Weather21°C (71°F)68 mm (2.7 inches)75%extreme
June Weather26°C (78°F)55 mm (2.2 inches)79%extreme
July Weather27°C (81°F)30 mm (1.2 inches)78%extreme
August Weather27°C (80°F)35 mm (1.4 inches)71%extreme
September Weather23°C (74°F)57 mm (2.3 inches)69%very high
October Weather16°C (61°F)46 mm (1.8 inches)70%very high
November Weather10°C (51°F)16 mm (0.6 inches)82%high
December Weather7°C (44°F)19 mm (0.7 inches)82%moderate

Compare Petersburg's Climate with Cities Worldwide