nomadseason

September Weather in Petersburg, United States

Last updated: June 24, 2025

In September, the average temperature in Petersburg, United States is a pleasant 23°C (74°F). However, you can expect a range, with minimum temperatures dipping to 8°C (47°F) and soaring to a maximum of 36°C (97°F). During this month, you might experience 102 mm (4.0 in) of precipitation over approximately 10 days, with an average humidity level of 75%. Enjoy the versatility of the weather as you explore this vibrant destination!

September Temperature in Petersburg

In September in Petersburg, the average temperature is 23°C (74°F). The maximum can reach 36°C (97°F) and the minimum can be as low as 8°C (47°F). This makes it an ideal destination for travelers seeking warm weather, but be prepared for 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 (74°F), with highs reaching up to 36°C (97°F) and lows dropping to around 8°C (47°F).
JanFebMarAprMayJunJulAugSepOctNovDec414650606976817873645044
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 102 mm (4.0 in) falling over the course of 10 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 102 mm (4.0 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec75100771061071141171601021277694
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 75%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket wrapping around you, making it feel more sweltering than it actually is, which can be quite uncomfortable for traveling.

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 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%84%84%82%83%83%79%77%75%81%87%85%
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.
JanFebMarAprMayJunJulAugSepOctNovDec3679101010109853
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)75 mm (3.0 inches)84%moderate
February Weather8°C (46°F)99 mm (3.9 inches)84%high
March Weather10°C (51°F)77 mm (3.0 inches)84%high
April Weather16°C (60°F)106 mm (4.2 inches)82%very high
May Weather20°C (69°F)107 mm (4.2 inches)82%very high
June Weather24°C (76°F)114 mm (4.5 inches)83%very high
July Weather27°C (81°F)116 mm (4.6 inches)79%very high
August Weather26°C (79°F)160 mm (6.3 inches)77%very high
September Weather23°C (74°F)102 mm (4.0 inches)75%very high
October Weather18°C (64°F)127 mm (5.0 inches)81%very high
November Weather10°C (50°F)76 mm (3.0 inches)87%moderate
December Weather7°C (45°F)94 mm (3.7 inches)85%moderate

Compare Petersburg's Climate with Cities Worldwide