September Weather in Reservoir, United States

Last updated: June 24, 2025

In Reservoir, United States, the average temperature in September hovers around 18°C (65°F), creating a pleasant atmosphere for outdoor activities. Expect temperatures to vary from a refreshing 1°C (34°F) to a warm 31°C (88°F). This month also sees approximately 130 mm (5.1 in) of precipitation spread over 11 days, contributing to an average humidity level of 67%. Enjoy the seasonal nuances while exploring this vibrant locale!

September Temperature in Reservoir

In September in Reservoir, the average temperature is 18°C (65°F). Maximums can reach 31°C (88°F), while minimums can drop as low as 1°C (34°F). Be prepared for a wide range of temperatures for your travels!

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

The chart illustrates September temperature patterns in Reservoir, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Reservoir, September typically has an average temperature of 18°C (65°F), with highs reaching up to 31°C (88°F) and lows dropping to around 1°C (34°F).

Data source: Temperature data for Reservoir generated using information from the Copernicus Climate Change Service.

September Precipitation in Reservoir

In Reservoir in September, the total precipitation amount is 130 mm (5.1 in) occurring over 11 days.

September Precipitation Trends in Reservoir

The chart displays monthly precipitation patterns in Reservoir, 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 Reservoir, September typically receives around 130 mm (5.1 inches) of precipitation spread over approximately 11 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Reservoir

In Reservoir in September humidity is 67%. With an average temperature of 18°C (65°F), this humidity feels like a mild blanket wrapping around you, making outdoor activities feel pleasantly refreshing, yet you may find yourself reaching for a drink more often to stay hydrated while exploring the sights.

September Average Humidity in Reservoir

This chart illustrates the average monthly humidity levels in Reservoir, 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 Reservoir is approximately 67%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Reservoir

In Reservoir in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Reservoir.

Maximum UV Index Levels in Reservoir for September

The chart shows the monthly maximum UV Index (UVI) for Reservoir 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 Reservoir typically reaches 8, which falls under the very high exposure category.

Data source: Reservoir 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 Reservoir Compares to Other Months

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

This table compares monthly weather conditions in Reservoir, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-2°C (28°F)	73 mm (2.9 inches)	89%	moderate
February Weather	0°C (32°F)	112 mm (4.4 inches)	90%	moderate
March Weather	3°C (38°F)	96 mm (3.8 inches)	89%	high
April Weather	9°C (49°F)	115 mm (4.5 inches)	88%	very high
May Weather	15°C (60°F)	139 mm (5.5 inches)	80%	very high
June Weather	20°C (68°F)	117 mm (4.6 inches)	79%	very high
July Weather	23°C (73°F)	119 mm (4.7 inches)	74%	very high
August Weather	22°C (71°F)	97 mm (3.8 inches)	64%	very high
September Weather	18°C (65°F)	130 mm (5.1 inches)	67%	very high
October Weather	12°C (54°F)	114 mm (4.5 inches)	81%	high
November Weather	4°C (39°F)	80 mm (3.1 inches)	89%	moderate
December Weather	1°C (33°F)	97 mm (3.8 inches)	88%	moderate