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September Weather in Grand Ronde, United States

Last updated: June 24, 2025

In September, the average temperature in Grand Ronde, United States is a pleasant 16°C (61°F). Expect minimums of around 4°C (40°F) and maximums soaring up to 35°C (95°F). During this time, anticipate 68 mm (2.7 in) of precipitation spread over 7 days, contributing to an average humidity of 71%. Stay prepared for a mix of weather as you enjoy this vibrant locale!

September Temperature in Grand Ronde

In September in Grand Ronde, the average temperature is 16°C (61°F). Maximums can reach 35°C (95°F), and minimums can be as low as 4°C (40°F). Be prepared for a wide range of temperatures when traveling to Grand Ronde this month.

September Weather in Grand Ronde: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Grand Ronde, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grand Ronde, September typically has an average temperature of 16°C (61°F), with highs reaching up to 35°C (95°F) and lows dropping to around 4°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec414044495560656661524541
Data source: Temperature data for Grand Ronde 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 Grand Ronde

In Grand Ronde in September, the precipitation amount is 68 mm (2.7 in) over the course of 7 days.

September Precipitation Trends in Grand Ronde

The chart displays monthly precipitation patterns in Grand Ronde, 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 Grand Ronde, September typically receives around 68 mm (2.7 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec19418015012663495668105178210
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Grand Ronde

In Grand Ronde in September humidity is 71%. With an average temperature of 16°C (61°F), this humidity feels like walking through a warm, damp blanket, making travel slightly uncomfortable but still enjoyable for those who appreciate mild weather.

September Average Humidity in Grand Ronde

This chart illustrates the average monthly humidity levels in Grand Ronde, 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 Grand Ronde is approximately 71%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%84%85%83%83%84%82%74%71%81%87%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Grand Ronde

In Grand Ronde 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 Grand Ronde.

Maximum UV Index Levels in Grand Ronde for September

The chart shows the monthly maximum UV Index (UVI) for Grand Ronde 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 Grand Ronde typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec23579101097532
Data source: Grand Ronde 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 Grand Ronde Compares to Other Months

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

This table compares monthly weather conditions in Grand Ronde, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)194 mm (7.6 inches)85%low
February Weather5°C (41°F)180 mm (7.1 inches)84%moderate
March Weather7°C (45°F)150 mm (5.9 inches)85%moderate
April Weather9°C (49°F)126 mm (4.9 inches)83%high
May Weather13°C (55°F)63 mm (2.5 inches)83%very high
June Weather16°C (61°F)49 mm (1.9 inches)83%very high
July Weather18°C (65°F)5 mm (0.2 inches)82%very high
August Weather19°C (66°F)6 mm (0.2 inches)74%very high
September Weather16°C (61°F)68 mm (2.7 inches)71%high
October Weather11°C (52°F)105 mm (4.1 inches)81%moderate
November Weather7°C (46°F)178 mm (7.0 inches)87%moderate
December Weather5°C (41°F)210 mm (8.3 inches)87%low

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