September Weather in Redlands, United States

Last updated: June 24, 2025

In September, the average temperature in Redlands, United States hovers around 19°C (66°F), with lows dipping to 0°C (33°F) and highs soaring up to 35°C (95°F). Expect 39 mm (1.5 in) of precipitation spread across about 5 days, contributing to an average humidity of 53%. Stay prepared for a mix of weather conditions!

September Temperature in Redlands

In September in Redlands, the average temperature is 19°C (66°F). Maximums can reach 35°C (95°F), while minimums can drop as low as 0°C (33°F). Travelers should be prepared for a wide range of temperatures, making layering essential for comfort during their visit.

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

The chart illustrates September temperature patterns in Redlands, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Redlands, September typically has an average temperature of 19°C (66°F), with highs reaching up to 35°C (95°F) and lows dropping to around 0°C (33°F).

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

September Precipitation in Redlands

In Redlands in September, the precipitation amount is 39 mm (1.5 in) spread over a duration of 5 days.

September Precipitation Trends in Redlands

The chart displays monthly precipitation patterns in Redlands, 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 Redlands, September typically receives around 39 mm (1.5 inches) of precipitation spread over approximately 5 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Redlands

In Redlands in September, humidity is 53%. With an average temperature of 19°C (66°F), this humidity feels like a refreshing breeze that enhances the pleasant warmth, making it ideal for exploring the sights and enjoying outdoor activities without feeling overly sticky or uncomfortable.

September Average Humidity in Redlands

This chart illustrates the average monthly humidity levels in Redlands, 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 Redlands is approximately 53%, 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 Redlands

In Redlands 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 Redlands.

Maximum UV Index Levels in Redlands for September

The chart shows the monthly maximum UV Index (UVI) for Redlands 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 Redlands typically reaches 10, which falls under the very high exposure category.

Data source: Redlands 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 Redlands Compares to Other Months

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

This table compares monthly weather conditions in Redlands, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	39 mm (1.5 inches)	90%	moderate
February Weather	-1°C (30°F)	49 mm (1.9 inches)	89%	high
March Weather	4°C (40°F)	68 mm (2.7 inches)	81%	very high
April Weather	10°C (50°F)	30 mm (1.2 inches)	74%	very high
May Weather	15°C (60°F)	43 mm (1.7 inches)	58%	extreme
June Weather	22°C (72°F)	26 mm (1.0 inches)	47%	extreme
July Weather	25°C (77°F)	34 mm (1.3 inches)	39%	extreme
August Weather	24°C (75°F)	29 mm (1.2 inches)	39%	extreme
September Weather	19°C (66°F)	39 mm (1.5 inches)	53%	very high
October Weather	9°C (49°F)	55 mm (2.2 inches)	72%	high
November Weather	4°C (40°F)	22 mm (0.9 inches)	84%	moderate
December Weather	-2°C (29°F)	37 mm (1.5 inches)	90%	moderate