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September Weather in Idalou, United States

Last updated: June 24, 2025

In September, the average temperature in Idalou, United States is a comfortable 23°C (74°F). However, temperatures can range from a brisk 4°C (40°F) to a sweltering 36°C (98°F). During this month, expect about 57 mm (2.2 in) of precipitation spread over 6 days, contributing to an overall average humidity of 69%.

September Temperature in Idalou

In September in Idalou, the average temperature is 23°C (74°F), with maximums reaching 36°C (98°F) and minimums dropping as low as 4°C (40°F). Be prepared for both warm days and cool nights when planning your travels.

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

The chart illustrates September temperature patterns in Idalou, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Idalou, September typically has an average temperature of 23°C (74°F), with highs reaching up to 36°C (98°F) and lows dropping to around 4°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec404354607178818073615044
Data source: Temperature data for Idalou 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 Idalou

In Idalou in September, the precipitation amount is 57 mm (2.2 in) over a span of 6 days.

September Precipitation Trends in Idalou

The chart displays monthly precipitation patterns in Idalou, 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 Idalou, September typically receives around 57 mm (2.2 inches) of precipitation spread over approximately 6 days.
JanFebMarAprMayJunJulAugSepOctNovDec171244316447283357511616
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Idalou

In Idalou in September humidity is 69%. With an average temperature of 23°C (74°F), this humidity feels like a warm embrace, making outdoor adventures enjoyable yet slightly sticky, perfect for leisurely strolls or exploring local attractions while staying hydrated.

September Average Humidity in Idalou

This chart illustrates the average monthly humidity levels in Idalou, 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 Idalou is approximately 69%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec75%74%66%70%75%79%78%71%69%70%82%82%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Idalou

In Idalou in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Idalou.

Maximum UV Index Levels in Idalou for September

The chart shows the monthly maximum UV Index (UVI) for Idalou 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 Idalou typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec579111112121210864
Data source: Idalou 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 Idalou Compares to Other Months

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

This table compares monthly weather conditions in Idalou, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)17 mm (0.6 inches)75%moderate
February Weather6°C (43°F)12 mm (0.5 inches)74%high
March Weather12°C (54°F)44 mm (1.7 inches)66%very high
April Weather16°C (61°F)31 mm (1.2 inches)70%extreme
May Weather21°C (71°F)64 mm (2.5 inches)75%extreme
June Weather26°C (78°F)47 mm (1.9 inches)79%extreme
July Weather27°C (81°F)28 mm (1.1 inches)78%extreme
August Weather27°C (80°F)33 mm (1.3 inches)71%extreme
September Weather23°C (74°F)57 mm (2.2 inches)69%very high
October Weather16°C (61°F)51 mm (2.0 inches)70%very high
November Weather10°C (51°F)16 mm (0.6 inches)82%high
December Weather7°C (44°F)16 mm (0.6 inches)82%moderate

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