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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 18°C (65°F). Expect variations with a minimum of 1°C (34°F) and a peak at 35°C (95°F). You'll also encounter a precipitation amount of 112 mm (4.4 in) spread across 10 days, alongside an average humidity of 79%. Be prepared for a mix of mild warmth and dampness!

September Temperature in Lyons

In September in Lyons, the average temperature is 18°C (65°F). Maximums can reach 35°C (95°F), while minimums can be as low as 1°C (34°F). This diverse temperature range makes Lyons an ideal destination for travelers looking to experience both warm days and cooler nights.

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 18°C (65°F), with highs reaching up to 35°C (95°F) and lows dropping to around 1°C (34°F).
JanFebMarAprMayJunJulAugSepOctNovDec252636465970757265533831
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 112 mm (4.4 in) over the course of 10 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 112 mm (4.4 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec6566648712911868671121276364
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 79%. With an average temperature of 18°C (65°F), this humidity feels like walking through a warm mist, making traveling slightly uncomfortable and sticky, but offering a refreshing escape when you find moments of shade or a breeze.

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 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%87%86%87%82%81%78%79%80%82%87%86%
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 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check 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 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec24589101097532
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-4°C (25°F)64 mm (2.5 inches)87%low
February Weather-3°C (27°F)66 mm (2.6 inches)87%moderate
March Weather2°C (37°F)64 mm (2.5 inches)86%moderate
April Weather8°C (47°F)87 mm (3.4 inches)87%very high
May Weather15°C (60°F)129 mm (5.1 inches)82%very high
June Weather21°C (70°F)118 mm (4.6 inches)81%very high
July Weather24°C (75°F)68 mm (2.7 inches)78%very high
August Weather22°C (72°F)66 mm (2.6 inches)79%very high
September Weather18°C (65°F)112 mm (4.4 inches)79%high
October Weather11°C (53°F)127 mm (5.0 inches)82%moderate
November Weather3°C (38°F)63 mm (2.5 inches)87%moderate
December Weather0°C (32°F)64 mm (2.5 inches)86%low

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