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September Weather in Lyons, United States

Last updated: June 24, 2025

In Lyons, United States, the average temperature in September hovers around 20°C (68°F), but you can expect a range from a chilly 5°C (40°F) to a sweltering 35°C (96°F). During this month, the region experiences approximately 82 mm (3.2 in) of precipitation over 9 days, contributing to an average humidity of 75%. Whether you're packing for a cool day or a warm one, be prepared for the unpredictable weather!

September Temperature in Lyons

In September in Lyons, the average temperature is 20°C (68°F). Maximums can reach 35°C (96°F) and minimums can be as low as 5°C (40°F). Be prepared for warm days and cool evenings when traveling to Lyons during this time.

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

The chart illustrates September temperature patterns in Lyons, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lyons, September typically has an average temperature of 20°C (68°F), with highs reaching up to 35°C (96°F) and lows dropping to around 5°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec242339486175777368513830
Data source: Temperature data for Lyons 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 Lyons

In Lyons in September, the total precipitation amount is 82 mm (3.2 in), occurring over a span of 9 days.

September Precipitation Trends in Lyons

The chart displays monthly precipitation patterns in Lyons, 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 Lyons, September typically receives around 82 mm (3.2 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec303088711511226911582872844
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Lyons

In Lyons in September, humidity is 75%. With an average temperature of 20°C (68°F), this humidity feels like a warm, muggy embrace that can leave travelers feeling sticky and exhausted.

September Average Humidity in Lyons

This chart illustrates the average monthly humidity levels in Lyons, 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 Lyons is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%80%73%75%78%82%83%81%75%75%82%83%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Lyons

In Lyons 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 Lyons.

Maximum UV Index Levels in Lyons for September

The chart shows the monthly maximum UV Index (UVI) for Lyons 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 Lyons typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec34689101098642
Data source: Lyons 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 Lyons Compares to Other Months

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

This table compares monthly weather conditions in Lyons, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-5°C (24°F)30 mm (1.2 inches)76%moderate
February Weather-5°C (24°F)30 mm (1.2 inches)80%moderate
March Weather4°C (39°F)87 mm (3.4 inches)73%high
April Weather9°C (48°F)71 mm (2.8 inches)74%very high
May Weather16°C (61°F)151 mm (5.9 inches)78%very high
June Weather24°C (75°F)122 mm (4.8 inches)82%very high
July Weather25°C (77°F)69 mm (2.7 inches)83%very high
August Weather23°C (73°F)115 mm (4.5 inches)80%very high
September Weather20°C (68°F)82 mm (3.2 inches)75%very high
October Weather11°C (51°F)87 mm (3.4 inches)75%high
November Weather4°C (39°F)28 mm (1.1 inches)82%moderate
December Weather-1°C (30°F)44 mm (1.7 inches)83%low

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