September Weather in Redwood, United States

Last updated: June 24, 2025

In {Redwood}, {United States}, the average temperature for {September} hovers around 27°C (80°F). Expect a range that dips to a cool 12°C (53°F) and can soar to a sizzling 38°C (100°F). During this month, you can anticipate about 109 mm (4.3 in) of precipitation spread over 12 days, with an average humidity of 65%. Stay prepared for a mix of warmth and occasional rainfall!

September Temperature in Redwood

In September in Redwood, the average temperature is 27°C (80°F). Maximums can reach as high as 38°C (100°F), and minimums can be as low as 12°C (53°F). Be sure to pack both light clothing for the heat and warmer layers for the cooler evenings while traveling.

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

The chart illustrates September temperature patterns in Redwood, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Redwood, September typically has an average temperature of 27°C (80°F), with highs reaching up to 38°C (100°F) and lows dropping to around 12°C (53°F).

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

September Precipitation in Redwood

In Redwood in September, the total precipitation amount is 109 mm (4.3 in) during a span of 12 days.

September Precipitation Trends in Redwood

The chart displays monthly precipitation patterns in Redwood, 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 Redwood, September typically receives around 109 mm (4.3 inches) of precipitation spread over approximately 12 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 Redwood

In Redwood in September humidity is 65%. With an average temperature of 27°C (80°F), this humidity feels like a warm blanket wrapped around you, making outdoor exploration a bit sticky but still enjoyable. The air feels thick and slightly heavy, which can lead to quicker fatigue during sightseeing, so it’s wise to stay hydrated and take breaks in the shade.

September Average Humidity in Redwood

This chart illustrates the average monthly humidity levels in Redwood, 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 Redwood is approximately 65%, 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 Redwood

In Redwood in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Redwood.

Maximum UV Index Levels in Redwood for September

The chart shows the monthly maximum UV Index (UVI) for Redwood 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 Redwood typically reaches 11, which falls under the extreme exposure category.

Data source: Redwood 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 Redwood Compares to Other Months

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

This table compares monthly weather conditions in Redwood, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (53°F)	46 mm (1.8 inches)	79%	moderate
February Weather	12°C (54°F)	57 mm (2.2 inches)	79%	very high
March Weather	18°C (65°F)	61 mm (2.4 inches)	74%	very high
April Weather	21°C (69°F)	92 mm (3.6 inches)	76%	extreme
May Weather	25°C (77°F)	136 mm (5.4 inches)	81%	extreme
June Weather	28°C (82°F)	95 mm (3.7 inches)	76%	extreme
July Weather	29°C (85°F)	78 mm (3.1 inches)	66%	extreme
August Weather	30°C (86°F)	96 mm (3.8 inches)	58%	extreme
September Weather	27°C (80°F)	109 mm (4.3 inches)	65%	extreme
October Weather	22°C (71°F)	85 mm (3.4 inches)	74%	very high
November Weather	16°C (61°F)	51 mm (2.0 inches)	81%	high
December Weather	13°C (56°F)	67 mm (2.6 inches)	86%	moderate