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September Weather in Bethalto, United States

Last updated: June 24, 2025

In September, the average temperature in Bethalto, United States is a pleasant 22°C (72°F). However, temperatures can range from a cool 7°C (44°F) to a warm 34°C (94°F), so be prepared for fluctuations! With an average precipitation of 64 mm (2.5 in) over about 6 days, you might encounter some rain. Don't forget that the average humidity sits at a comfortable 76%, adding to the region's unique climate.

September Temperature in Bethalto

In September in Bethalto, the average temperature is 22°C (72°F), with maximums reaching up to 34°C (94°F) and minimums dropping as low as 7°C (44°F). This comfortable climate makes Bethalto an ideal destination for travelers looking to enjoy a variety of outdoor activities.

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

The chart illustrates September temperature patterns in Bethalto, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bethalto, September typically has an average temperature of 22°C (72°F), with highs reaching up to 34°C (94°F) and lows dropping to around 7°C (44°F).
JanFebMarAprMayJunJulAugSepOctNovDec313446546776797672594338
Data source: Temperature data for Bethalto 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 Bethalto

In Bethalto in September, the total precipitation amount is 64 mm (2.5 in) during a span of 6 days.

September Precipitation Trends in Bethalto

The chart displays monthly precipitation patterns in Bethalto, 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 Bethalto, September typically receives around 64 mm (2.5 inches) of precipitation spread over approximately 6 days.
JanFebMarAprMayJunJulAugSepOctNovDec7580133132156111100120641037557
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Bethalto

In Bethalto in September humidity is 76%. With an average temperature of 22°C (72°F), this humidity feels like a warm embrace, making travel slightly uncomfortable as you navigate through the thick, saturated air.

September Average Humidity in Bethalto

This chart illustrates the average monthly humidity levels in Bethalto, 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 Bethalto is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bethalto

In Bethalto 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 Bethalto.

Maximum UV Index Levels in Bethalto for September

The chart shows the monthly maximum UV Index (UVI) for Bethalto 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 Bethalto typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910111199643
Data source: Bethalto 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 Bethalto Compares to Other Months

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

This table compares monthly weather conditions in Bethalto, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)75 mm (3.0 inches)82%moderate
February Weather1°C (35°F)80 mm (3.1 inches)80%moderate
March Weather8°C (46°F)133 mm (5.2 inches)80%high
April Weather12°C (55°F)132 mm (5.2 inches)80%very high
May Weather19°C (67°F)156 mm (6.1 inches)82%very high
June Weather25°C (77°F)111 mm (4.4 inches)83%extreme
July Weather26°C (79°F)100 mm (3.9 inches)81%extreme
August Weather24°C (76°F)120 mm (4.7 inches)80%very high
September Weather22°C (72°F)64 mm (2.5 inches)76%very high
October Weather15°C (59°F)102 mm (4.0 inches)76%high
November Weather6°C (44°F)75 mm (2.9 inches)85%moderate
December Weather3°C (38°F)57 mm (2.2 inches)86%moderate

Compare Bethalto's Climate with Cities Worldwide