September Weather in Barstow, United States

Last updated: June 24, 2025

In September, the average temperature in Barstow, United States is a warm 27°C (80°F), providing a pleasant atmosphere for outdoor activities. However, temperatures can fluctuate, with a minimum of 7°C (45°F) and a scorching maximum of 43°C (110°F). Expect minimal rain, with just 1 mm (0.0 in) of precipitation over 0 days, and enjoy the comfortable average humidity of 41%.

September Temperature in Barstow

In September in Barstow, the average temperature is 27°C (80°F). Maximums can reach 43°C (110°F), and minimums can be as low as 7°C (45°F). Be prepared for a wide range of temperatures when traveling to Barstow during this month.

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

The chart illustrates September temperature patterns in Barstow, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Barstow, September typically has an average temperature of 27°C (80°F), with highs reaching up to 43°C (110°F) and lows dropping to around 7°C (45°F).

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

September Precipitation in Barstow

In Barstow in September, the precipitation amount is 1 mm (0.0 in) during a span of 0 days.

September Precipitation Trends in Barstow

The chart displays monthly precipitation patterns in Barstow, 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 Barstow, September typically receives around 1 mm (0.0 inches) of precipitation spread over approximately 0 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 Barstow

In Barstow in September, humidity is 41%. With an average temperature of 27°C (80°F), this humidity feels like a warm embrace, making outdoor activities enjoyable while still requiring a light layer to stay comfortable during the day.

September Average Humidity in Barstow

This chart illustrates the average monthly humidity levels in Barstow, 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 Barstow is approximately 41%, 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 Barstow

In Barstow 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 Barstow.

Maximum UV Index Levels in Barstow for September

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

Data source: Barstow 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 Barstow Compares to Other Months

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

This table compares monthly weather conditions in Barstow, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (49°F)	22 mm (0.9 inches)	76%	moderate
February Weather	11°C (51°F)	13 mm (0.5 inches)	80%	high
March Weather	14°C (57°F)	17 mm (0.7 inches)	69%	very high
April Weather	18°C (65°F)	11 mm (0.4 inches)	57%	very high
May Weather	22°C (71°F)	3 mm (0.1 inches)	45%	extreme
June Weather	28°C (83°F)	1 mm (0.0 inches)	34%	extreme
July Weather	31°C (89°F)	3 mm (0.1 inches)	29%	extreme
August Weather	31°C (88°F)	1 mm (0.0 inches)	28%	extreme
September Weather	27°C (80°F)	1 mm (0.0 inches)	41%	very high
October Weather	19°C (67°F)	2 mm (0.1 inches)	54%	very high
November Weather	14°C (57°F)	6 mm (0.2 inches)	68%	moderate
December Weather	8°C (47°F)	19 mm (0.7 inches)	75%	moderate