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September Weather in West Richland, United States

Last updated: June 24, 2025

In September, the average temperature in West Richland, United States hovers around 20°C (69°F). Temperatures can vary significantly, with a minimum of 5°C (42°F) and a sweltering maximum of 39°C (103°F). Expect light rain, with an average precipitation of 8 mm (0.3 in) spread over 2 days. The average humidity during this time is around 60%, making for a comfortable climate overall.

September Temperature in West Richland

In September in West Richland, the average temperature is 20°C (69°F). Maximum temperatures can reach 39°C (103°F), while minimums can drop as low as 5°C (42°F). This variability makes West Richland a destination perfect for travelers who enjoy both warm days and cooler evenings.

September Weather in West Richland: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in West Richland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In West Richland, September typically has an average temperature of 20°C (69°F), with highs reaching up to 39°C (103°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec353646566674828069544236
Data source: Temperature data for West Richland 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 West Richland

In West Richland in September, the precipitation amount is 8 mm (0.3 in) over the course of 2 days.

September Precipitation Trends in West Richland

The chart displays monthly precipitation patterns in West Richland, 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 West Richland, September typically receives around 8 mm (0.3 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec36392622137038233030
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in West Richland

In West Richland in September humidity is 60%. With an average temperature of 20°C (69°F), this humidity feels like a warm embrace, making it quite pleasant for traveling, as the air is soft and invigorating, perfect for exploring the sights and enjoying the local culture without feeling overwhelmed.

September Average Humidity in West Richland

This chart illustrates the average monthly humidity levels in West Richland, 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 West Richland is approximately 60%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%86%86%82%77%79%77%62%60%80%87%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in West Richland

In West Richland 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 West Richland.

Maximum UV Index Levels in West Richland for September

The chart shows the monthly maximum UV Index (UVI) for West Richland 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 West Richland typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2356991097532
Data source: West Richland 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 West Richland Compares to Other Months

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

This table compares monthly weather conditions in West Richland, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather2°C (35°F)36 mm (1.4 inches)85%low
February Weather2°C (37°F)39 mm (1.5 inches)86%moderate
March Weather8°C (47°F)26 mm (1.0 inches)86%moderate
April Weather13°C (56°F)22 mm (0.9 inches)82%high
May Weather19°C (67°F)13 mm (0.5 inches)77%very high
June Weather24°C (75°F)7 mm (0.3 inches)79%very high
July Weather28°C (82°F)0 mm (0.0 inches)77%very high
August Weather27°C (80°F)3 mm (0.1 inches)62%very high
September Weather20°C (69°F)8 mm (0.3 inches)60%high
October Weather12°C (54°F)23 mm (0.9 inches)80%moderate
November Weather6°C (42°F)30 mm (1.2 inches)87%moderate
December Weather2°C (36°F)30 mm (1.2 inches)86%low

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