September Weather in Fort Irwin, United States

Last updated: June 24, 2025

In Fort Irwin, United States, the average temperature in September typically hovers around 27°C (80°F). However, temperatures can vary dramatically, with minimums dipping to 8°C (46°F) and maximums soaring up to 43°C (110°F). Rainfall is minimal, with an average precipitation of just 1 mm (0.0 in) over 0 days. In terms of comfort, expect an average humidity of 41%.

September Temperature in Fort Irwin

In September in Fort Irwin, the average temperature is 27°C (80°F), with highs soaring up to 43°C (110°F) and lows dipping to as low as 8°C (46°F). Be sure to prepare for a wide range of temperatures during your travels, and pack accordingly!

September Weather in Fort Irwin: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Fort Irwin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fort Irwin, 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 8°C (46°F).

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

September Precipitation in Fort Irwin

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

September Precipitation Trends in Fort Irwin

The chart displays monthly precipitation patterns in Fort Irwin, 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 Fort Irwin, 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 Fort Irwin

In Fort Irwin 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 Fort Irwin

This chart illustrates the average monthly humidity levels in Fort Irwin, 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 Fort Irwin 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 Fort Irwin

In Fort Irwin 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 Fort Irwin.

Maximum UV Index Levels in Fort Irwin for September

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

Data source: Fort Irwin 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 Fort Irwin Compares to Other Months

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

This table compares monthly weather conditions in Fort Irwin, 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 (48°F)	22 mm (0.9 inches)	76%	moderate
February Weather	10°C (51°F)	15 mm (0.6 inches)	80%	high
March Weather	13°C (57°F)	17 mm (0.7 inches)	69%	very high
April Weather	18°C (65°F)	12 mm (0.5 inches)	57%	very high
May Weather	22°C (72°F)	4 mm (0.2 inches)	45%	extreme
June Weather	28°C (83°F)	1 mm (0.0 inches)	34%	extreme
July Weather	32°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)	3 mm (0.1 inches)	54%	high
November Weather	13°C (56°F)	6 mm (0.2 inches)	68%	moderate
December Weather	8°C (46°F)	18 mm (0.7 inches)	75%	moderate