September weather forecast
Los Angeles, CA

September in Los Angeles, California, observes a shift from the intense summer weather to the moderately warm autumn season. Despite the decrease in daylight hours, the average temperature refuses to lower significantly, keeping the days quite warm. It is observed that the cloud cover in September increases to 9% from August's 6%, attempting to tame the striking summer sun. All the while, the wind speeds remain nearly constant from August, maintaining the city's calm atmosphere. Therefore, September exemplifies the subtle onset of autumn, with the weather remaining significantly warm while gradually cooling down.

Temperature

Los Angeles commences September with an average high-temperature of a still moderately hot 82.2°F (27.9°C), maintaining a close resemblance to the previous month. Los Angeles's temperature tends to fall to an average low of 64.4°F (18°C) during the nights of September.

Heat index

September's average heat index is appraised at 84.2°F (29°C). Long-standing exposure coupled with ongoing activity could result in exhaustion, possibly causing heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', is a measure of how hot it feels when the actual air humidity is factored in. This effect is personal, shaped by the individual's physical activity and heat sensitivity, influenced by factors including wind, clothing, and metabolic variances. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.

Humidity

The average relative humidity in September in Los Angeles, California, is 57%.

Rainfall

In Los Angeles, during September, the rain falls for 2.1 days and regularly aggregates up to 0.12" (3mm) of precipitation. In Los Angeles, during the entire year, the rain falls for 44.6 days and collects up to 8.11" (206mm) of precipitation.

Daylight

The average length of the day in September is 12h and 22min.
On the first day of September in Los Angeles, sunrise is at 6:27 am and sunset at 7:18 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:38 pm PDT.

Sunshine

In September, the average sunshine is 10.7h.

UV index

June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, a daily UV index of 6 turns into the following recommendations:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.