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September Weather in Jamestown, United States

Last updated: June 24, 2025

In September, the average temperature in Jamestown, United States hovers around 22°C (72°F), providing a comfortable environment for outdoor activities. However, temperatures can range from a brisk 6°C (43°F) to a sweltering 35°C (95°F), so be prepared for fluctuating weather. Expect an average precipitation of 121 mm (4.8 in) over 10 days, contributing to a humidity level of 71% that adds a touch of warmth to the air.

September Temperature in Jamestown

In September in Jamestown, the average temperature is 22°C (72°F). Maximums can reach 35°C (95°F), while minimums can dip as low as 6°C (43°F). This diverse range of temperatures makes Jamestown a great destination for travelers seeking both warmth and cooler respite.

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

The chart illustrates September temperature patterns in Jamestown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Jamestown, September typically has an average temperature of 22°C (72°F), with highs reaching up to 35°C (95°F) and lows dropping to around 6°C (43°F).
JanFebMarAprMayJunJulAugSepOctNovDec394451576873777571614744
Data source: Temperature data for Jamestown 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 Jamestown

In Jamestown in September, the precipitation amount is 121 mm (4.8 in) spread over a period of 10 days.

September Precipitation Trends in Jamestown

The chart displays monthly precipitation patterns in Jamestown, 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 Jamestown, September typically receives around 121 mm (4.8 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec10018815215514114213713812113374144
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Jamestown

In Jamestown in September humidity is 71%. With an average temperature of 22°C (72°F), this humidity feels like the air is thick and slightly stifling, making outdoor activities require frequent breaks to stay hydrated and cool.

September Average Humidity in Jamestown

This chart illustrates the average monthly humidity levels in Jamestown, 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 Jamestown is approximately 71%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%86%82%83%83%80%74%71%78%88%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Jamestown

In Jamestown 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 Jamestown.

Maximum UV Index Levels in Jamestown for September

The chart shows the monthly maximum UV Index (UVI) for Jamestown 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 Jamestown typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36710111111109753
Data source: Jamestown 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 Jamestown Compares to Other Months

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

This table compares monthly weather conditions in Jamestown, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather4°C (39°F)100 mm (3.9 inches)87%moderate
February Weather7°C (44°F)188 mm (7.4 inches)86%high
March Weather10°C (51°F)152 mm (6.0 inches)86%high
April Weather14°C (58°F)155 mm (6.1 inches)82%very high
May Weather20°C (68°F)141 mm (5.6 inches)82%extreme
June Weather23°C (74°F)142 mm (5.6 inches)83%extreme
July Weather25°C (78°F)137 mm (5.4 inches)80%extreme
August Weather24°C (76°F)138 mm (5.4 inches)74%very high
September Weather22°C (72°F)121 mm (4.8 inches)71%very high
October Weather16°C (62°F)133 mm (5.2 inches)78%high
November Weather8°C (47°F)74 mm (2.9 inches)88%moderate
December Weather6°C (44°F)144 mm (5.7 inches)88%moderate

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