September Weather in Bonsall, United States

Last updated: June 24, 2025

In September, the average temperature in Bonsall, United States is a pleasant 23°C (73°F). Temperatures can vary, dipping to a cool 13°C (55°F) at night and soaring to a sizzling 40°C (104°F) during the day. Expect a small amount of precipitation, averaging just 5 mm (0.2 in) over 1 day, and enjoy a comfortable average humidity of 52%.

September Temperature in Bonsall

In September, in Bonsall, the average temperature is 23°C (73°F). Maximums can reach 40°C (104°F), while minimums can drop as low as 13°C (55°F). Be prepared for warm weather and pack accordingly for both hot days and cooler nights during your travels.

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

The chart illustrates September temperature patterns in Bonsall, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bonsall, September typically has an average temperature of 23°C (73°F), with highs reaching up to 40°C (104°F) and lows dropping to around 13°C (55°F).

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

September Precipitation in Bonsall

In Bonsall in September, the precipitation amount is 5 mm (0.2 in) over a duration of 1 day.

September Precipitation Trends in Bonsall

The chart displays monthly precipitation patterns in Bonsall, 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 Bonsall, September typically receives around 5 mm (0.2 inches) of precipitation spread over approximately 1 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 Bonsall

In Bonsall in September humidity is 52%. With an average temperature of 23°C (73°F), this humidity feels like a comfortable embrace, making it pleasant for traveling as you can enjoy outdoor activities without feeling overheated or sticky.

September Average Humidity in Bonsall

This chart illustrates the average monthly humidity levels in Bonsall, 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 Bonsall is approximately 52%, 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 Bonsall

In Bonsall 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 Bonsall.

Maximum UV Index Levels in Bonsall for September

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

Data source: Bonsall 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 Bonsall Compares to Other Months

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

This table compares monthly weather conditions in Bonsall, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (56°F)	70 mm (2.8 inches)	72%	moderate
February Weather	13°C (56°F)	78 mm (3.1 inches)	77%	high
March Weather	14°C (58°F)	68 mm (2.7 inches)	67%	very high
April Weather	16°C (62°F)	32 mm (1.3 inches)	56%	very high
May Weather	17°C (63°F)	24 mm (0.9 inches)	46%	extreme
June Weather	20°C (68°F)	3 mm (0.1 inches)	48%	extreme
July Weather	23°C (73°F)	4 mm (0.2 inches)	46%	extreme
August Weather	24°C (75°F)	1 mm (0.1 inches)	42%	very high
September Weather	23°C (73°F)	5 mm (0.2 inches)	52%	very high
October Weather	20°C (69°F)	12 mm (0.5 inches)	58%	high
November Weather	17°C (63°F)	34 mm (1.4 inches)	66%	moderate
December Weather	14°C (57°F)	70 mm (2.7 inches)	74%	moderate