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September Weather in Bloomington, United States

Last updated: June 24, 2025

In Bloomington, United States, the average temperature in September is a pleasant 21°C (71°F). However, temperatures can dip as low as 6°C (44°F) or soar up to 34°C (93°F). Visitors should be prepared for a moderate amount of rain, with 73 mm (2.9 in) of precipitation expected over 7 days. Additionally, the air tends to be quite humid, averaging around 69%.

September Temperature in Bloomington

In September in Bloomington, the average temperature is 21°C (71°F), with maximums reaching 34°C (93°F) and minimums dropping as low as 6°C (44°F). This diverse temperature range makes it a perfect time for travelers to experience a variety of outdoor activities, from warm daytime excursions to cooler evening strolls.

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

The chart illustrates September temperature patterns in Bloomington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bloomington, September typically has an average temperature of 21°C (71°F), with highs reaching up to 34°C (93°F) and lows dropping to around 6°C (44°F).
JanFebMarAprMayJunJulAugSepOctNovDec323544536574777570584337
Data source: Temperature data for Bloomington 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 Bloomington

In Bloomington in September, the precipitation amount is 73 mm (2.9 in) during a span of 7 days.

September Precipitation Trends in Bloomington

The chart displays monthly precipitation patterns in Bloomington, 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 Bloomington, September typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec871061301151311321111007310210896
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Bloomington

In Bloomington in September humidity is 69%. With an average temperature of 21°C (71°F), this humidity feels like a warm embrace, creating a tropical atmosphere that can make outdoor activities feel slightly sticky, yet invigorating for travelers who are ready to embrace the local culture and explore.

September Average Humidity in Bloomington

This chart illustrates the average monthly humidity levels in Bloomington, 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 Bloomington is approximately 69%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%85%86%84%79%82%79%70%69%76%88%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bloomington

In Bloomington 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 Bloomington.

Maximum UV Index Levels in Bloomington for September

The chart shows the monthly maximum UV Index (UVI) for Bloomington 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 Bloomington typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357910111098643
Data source: Bloomington 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 Bloomington Compares to Other Months

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

This table compares monthly weather conditions in Bloomington, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)87 mm (3.4 inches)87%moderate
February Weather2°C (36°F)106 mm (4.2 inches)85%moderate
March Weather7°C (45°F)130 mm (5.1 inches)86%high
April Weather12°C (53°F)115 mm (4.5 inches)84%very high
May Weather18°C (65°F)131 mm (5.2 inches)79%very high
June Weather23°C (74°F)131 mm (5.2 inches)82%extreme
July Weather25°C (77°F)111 mm (4.4 inches)79%very high
August Weather24°C (75°F)100 mm (3.9 inches)70%very high
September Weather21°C (71°F)73 mm (2.9 inches)69%very high
October Weather15°C (59°F)101 mm (4.0 inches)76%high
November Weather6°C (43°F)108 mm (4.3 inches)88%moderate
December Weather3°C (38°F)96 mm (3.8 inches)87%moderate

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