nomadseason

September Weather in Richland, United States

Last updated: June 24, 2025

In September, the average temperature in Richland, United States hovers around 26°C (79°F). Visitors can expect a range from a cool 12°C (54°F) at night to a sizzling 37°C (98°F) during the day. With 102 mm (4.0 in) of precipitation spread over about 10 days, it's wise to prepare for some rain. Additionally, the average humidity stands at 83%, making it a tropical experience for those exploring this vibrant locale.

September Temperature in Richland

In September in Richland, the average temperature is 26°C (79°F), with maximums reaching 37°C (98°F) and minimums dropping to as low as 12°C (54°F). This diverse temperature range makes Richland a great destination for travelers seeking both warm days and cooler evenings.

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

The chart illustrates September temperature patterns in Richland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Richland, September typically has an average temperature of 26°C (79°F), with highs reaching up to 37°C (98°F) and lows dropping to around 12°C (54°F).
JanFebMarAprMayJunJulAugSepOctNovDec505661667479818178705752
Data source: Temperature data for Richland generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Richland

In Richland in September, the total precipitation amount is 102 mm (4.0 in) falling over the course of 10 days.

September Precipitation Trends in Richland

The chart displays monthly precipitation patterns in 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 Richland, September typically receives around 102 mm (4.0 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec9911492115939410911810211559130
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Richland

In Richland in September, humidity is 83%. With an average temperature of 26°C (79°F), this humidity feels like a heavy blanket enveloping you, making travel an exercise in endurance as the air clings to your skin and saps your energy.

September Average Humidity in Richland

This chart illustrates the average monthly humidity levels in 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 Richland is approximately 83%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%82%80%76%73%74%80%79%83%77%84%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Richland

In Richland 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 Richland.

Maximum UV Index Levels in Richland for September

The chart shows the monthly maximum UV Index (UVI) for 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 Richland typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec479101111111110864
Data source: 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 Richland Compares to Other Months

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

This table compares monthly weather conditions in Richland, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (50°F)99 mm (3.9 inches)85%moderate
February Weather13°C (57°F)114 mm (4.5 inches)82%high
March Weather16°C (61°F)92 mm (3.6 inches)80%very high
April Weather19°C (66°F)115 mm (4.5 inches)76%very high
May Weather23°C (75°F)93 mm (3.7 inches)73%extreme
June Weather26°C (79°F)94 mm (3.7 inches)74%extreme
July Weather27°C (82°F)109 mm (4.3 inches)80%extreme
August Weather27°C (81°F)118 mm (4.6 inches)79%extreme
September Weather26°C (79°F)102 mm (4.0 inches)83%very high
October Weather21°C (71°F)114 mm (4.5 inches)77%very high
November Weather14°C (57°F)59 mm (2.3 inches)84%high
December Weather11°C (53°F)130 mm (5.1 inches)88%moderate

Compare Richland's Climate with Cities Worldwide