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September Weather in Lake Ketchum, United States

Last updated: June 24, 2025

In September, the average temperature in Lake Ketchum, United States hovers around 15°C (60°F). Visitors can expect a minimum of 6°C (42°F) and a maximum of 30°C (86°F). With 127 mm (5.0 in) of precipitation spread across 11 days, the weather is sure to keep you on your toes. Moreover, the average humidity stands at a comfortable 76%, making it a pleasant time to explore!

September Temperature in Lake Ketchum

In September in Lake Ketchum, the average temperature is 15°C (60°F). Maximum temperatures can reach 30°C (86°F) while minimums can drop as low as 6°C (42°F). It's a great time for travelers to enjoy a mild climate, making it perfect for outdoor activities and exploration.

September Weather in Lake Ketchum: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Lake Ketchum, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lake Ketchum, September typically has an average temperature of 15°C (60°F), with highs reaching up to 30°C (86°F) and lows dropping to around 6°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec403844495560646459494439
Data source: Temperature data for Lake Ketchum 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 Lake Ketchum

In Lake Ketchum in September, the precipitation amount is 127 mm (5.0 in), occurring over 11 days.

September Precipitation Trends in Lake Ketchum

The chart displays monthly precipitation patterns in Lake Ketchum, 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 Lake Ketchum, September typically receives around 127 mm (5.0 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec21722217914583752226127204274255
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Lake Ketchum

In Lake Ketchum in September humidity is 76%. With an average temperature of 15°C (60°F), this humidity feels like a warm, damp blanket wrapping around you, making outdoor activities a bit more challenging and urging you to stay hydrated while exploring the area.

September Average Humidity in Lake Ketchum

This chart illustrates the average monthly humidity levels in Lake Ketchum, 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 Lake Ketchum is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%88%86%82%82%85%77%76%88%88%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Lake Ketchum

In Lake Ketchum 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 Lake Ketchum.

Maximum UV Index Levels in Lake Ketchum for September

The chart shows the monthly maximum UV Index (UVI) for Lake Ketchum 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 Lake Ketchum typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689987522
Data source: Lake Ketchum 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 Lake Ketchum Compares to Other Months

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

This table compares monthly weather conditions in Lake Ketchum, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (40°F)217 mm (8.5 inches)87%low
February Weather4°C (39°F)222 mm (8.7 inches)86%moderate
March Weather6°C (44°F)179 mm (7.0 inches)88%moderate
April Weather9°C (49°F)145 mm (5.7 inches)86%high
May Weather13°C (55°F)83 mm (3.3 inches)82%very high
June Weather15°C (60°F)75 mm (2.9 inches)82%very high
July Weather18°C (64°F)22 mm (0.9 inches)85%very high
August Weather18°C (65°F)26 mm (1.0 inches)77%very high
September Weather15°C (60°F)127 mm (5.0 inches)76%high
October Weather10°C (50°F)204 mm (8.0 inches)88%moderate
November Weather7°C (45°F)274 mm (10.8 inches)88%low
December Weather4°C (40°F)255 mm (10.0 inches)89%low

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