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September Weather in Napoleon, United States

Last updated: June 24, 2025

In September, the average temperature in Napoleon, United States hovers around 20°C (68°F), making it a comfortable time to explore. However, be prepared for fluctuations, with minimums dipping as low as 3°C (38°F) and maximums soaring up to 34°C (94°F). Expect 57 mm (2.2 in) of precipitation spread across 8 days, and embrace the humidity, which averages at a cozy 78%.

September Temperature in Napoleon

In September in Napoleon, the average temperature is 20°C (68°F). Maximum temperatures can reach 34°C (94°F), while minimums can dip as low as 3°C (38°F). Overall, it's an ideal time for travelers to enjoy a mix of warm days and cool nights in Napoleon.

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

The chart illustrates September temperature patterns in Napoleon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Napoleon, September typically has an average temperature of 20°C (68°F), with highs reaching up to 34°C (94°F) and lows dropping to around 3°C (38°F).
JanFebMarAprMayJunJulAugSepOctNovDec283039496271757368564134
Data source: Temperature data for Napoleon 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 Napoleon

In Napoleon in September, the precipitation amount is 57 mm (2.2 in) over the course of 8 days.

September Precipitation Trends in Napoleon

The chart displays monthly precipitation patterns in Napoleon, 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 Napoleon, September typically receives around 57 mm (2.2 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec697088931391121038857908156
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Napoleon

In Napoleon in September humidity is 78%. With an average temperature of 20°C (68°F), this humidity feels like a warm, enveloping blanket that makes exploring the sights a bit sticky, so travelers should stay hydrated and take frequent breaks in the shade.

September Average Humidity in Napoleon

This chart illustrates the average monthly humidity levels in Napoleon, 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 Napoleon 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 Napoleon

In Napoleon 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 Napoleon.

Maximum UV Index Levels in Napoleon for September

The chart shows the monthly maximum UV Index (UVI) for Napoleon 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 Napoleon typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35699101098642
Data source: Napoleon 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 Napoleon Compares to Other Months

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

This table compares monthly weather conditions in Napoleon, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (28°F)69 mm (2.7 inches)88%moderate
February Weather-1°C (30°F)70 mm (2.8 inches)87%moderate
March Weather4°C (40°F)88 mm (3.5 inches)87%high
April Weather9°C (49°F)93 mm (3.7 inches)87%very high
May Weather16°C (62°F)139 mm (5.5 inches)81%very high
June Weather22°C (72°F)112 mm (4.4 inches)82%very high
July Weather24°C (76°F)103 mm (4.0 inches)81%very high
August Weather23°C (73°F)88 mm (3.5 inches)78%very high
September Weather20°C (68°F)57 mm (2.2 inches)78%very high
October Weather13°C (56°F)90 mm (3.6 inches)82%high
November Weather5°C (41°F)81 mm (3.2 inches)89%moderate
December Weather1°C (34°F)56 mm (2.2 inches)86%low

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