September Weather in La Mesa, United States

Last updated: June 24, 2025

In September, the average temperature in La Mesa, United States is a pleasant 22°C (72°F). Expect a range from a cool 14°C (57°F) to a warm 38°C (101°F). During this month, precipitation is minimal at 4 mm (0.1 in) over just 1 day, and the average humidity hovers around 52%.

September Temperature in La Mesa

In September in La Mesa, the average temperature is 22°C (72°F), with maximums reaching 38°C (101°F) and minimums dipping as low as 14°C (57°F). This comfortable climate makes La Mesa an ideal destination for travelers looking to enjoy a pleasant getaway.

September Weather in La Mesa: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in La Mesa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In La Mesa, September typically has an average temperature of 22°C (72°F), with highs reaching up to 38°C (101°F) and lows dropping to around 14°C (57°F).

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

September Precipitation in La Mesa

In La Mesa in September, the precipitation amount is 4 mm (0.1 in) over the course of 1 day.

September Precipitation Trends in La Mesa

The chart displays monthly precipitation patterns in La Mesa, 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 La Mesa, September typically receives around 4 mm (0.1 inches) of precipitation spread over approximately 1 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 La Mesa

In La Mesa in September humidity is 52%. With an average temperature of 22°C (72°F), this humidity feels like a refreshing embrace during your travels, creating a pleasant sensation that makes outdoor activities enjoyable and inviting.

September Average Humidity in La Mesa

This chart illustrates the average monthly humidity levels in La Mesa, 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 La Mesa 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 La Mesa

In La Mesa 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 La Mesa.

Maximum UV Index Levels in La Mesa for September

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

Data source: La Mesa 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 La Mesa Compares to Other Months

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

This table compares monthly weather conditions in La Mesa, 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)	56 mm (2.2 inches)	72%	moderate
February Weather	13°C (56°F)	68 mm (2.7 inches)	77%	high
March Weather	14°C (57°F)	51 mm (2.0 inches)	67%	very high
April Weather	16°C (61°F)	24 mm (0.9 inches)	56%	very high
May Weather	17°C (63°F)	21 mm (0.8 inches)	46%	extreme
June Weather	19°C (67°F)	2 mm (0.1 inches)	48%	extreme
July Weather	22°C (72°F)	3 mm (0.1 inches)	46%	extreme
August Weather	23°C (74°F)	1 mm (0.1 inches)	42%	very high
September Weather	22°C (72°F)	4 mm (0.1 inches)	52%	very high
October Weather	20°C (68°F)	14 mm (0.6 inches)	58%	high
November Weather	17°C (62°F)	29 mm (1.1 inches)	66%	moderate
December Weather	14°C (57°F)	65 mm (2.5 inches)	74%	moderate