Los Angeles Weather in September

September continues the pleasant summer weather that Los Angeles, California enjoys. It's another month where you can expect plenty of sun, no rain and moderately hot temperatures.

This page gives detailed information on the typical September temperature, precipitation, sun, humidity, wind and storms for Los Angeles. The temperature, rainfall, sunshine and wind speed numbers here are historical averages based on climate data gathered in downtown Los Angeles near Union Station. The humidity and thunderstorm measurements are averages at the Los Angeles International Airport, located southwest of the city center.

Temperature Weather iconTemperature

83 °F September average high 28 °C
64 °F September average low 18 °C
21 days 80 °F max. or more (27 °C)
6 days 60 °F min. or less (16 °C)

Typically every day in September warms to over 70 degrees Fahrenheit (21 degrees Celsius) in Los Angeles. The city averages six days this month when the thermometer reaches into the 90s °F (over 32 °C). In some years, a temperature of 100 °F (38 °C) or more can occur briefly during September.

The thermometer drops to 70 °F (21 °C) or below on most nights. But September does not normally cool down to 50 °F (10 °C).

Rainy Weather iconRain

0.1 in total precipitation 3 mm
0 day of rain

Most years, Los Angeles gets no precipitation at all in September.

Sunny Weather iconSun

79 % sunshine
18 days clear skies

The sun's rays reach the ground in Los Angeles during 79 percent of daylight hours on average in September, for a total of 293 hours in the month. Typically on 18 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in September at Los Angeles lasts for 12 hours and 21 minutes a day on average. The longest day of the month is the 1st with 12 hours and 52 minutes of daylight. By the end of the month, the days have shortened to 11:51 from sunrise to sunset. These durations can vary by a minute or two from year to year.

Humid Weather iconHumidity

74 % September average humidity

The relative humidity in Los Angeles during September usually peaks at 83 percent in the morning then drops to 62 percent by early afternoon.

Local Time1 am4 am7 am10 am1 pm4 pm7 pm10 pm
Humidity % 82 83 80 65 62 67 77 80

Windy Weather iconWind

4.4 mph September wind speed average 7.1 kph

September is a little less windy than most other months in Los Angeles.

Stormy Weather iconStorms

0 days rainfall of 0.5 inches (13 mm) or more
1 day with thunderstorms in September

Los Angeles averages a September thunderstorm every two years, and a heavy rainstorm about once a decade.


The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.

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