September weather forecastUniversity Heights, CA
September
Weather in September
The first month of the autumn, September, is still a hot month in University Heights, California, with an average temperature varying between 63°F (17.2°C) and 87.8°F (31°C).Temperature
September's arrival brings an average high-temperature of a still tropical 87.8°F (31°C), slightly deviating from August's 91.9°F (33.3°C). In University Heights, the nighttime chill during September is a clear shift from the day's highs, with an average of 63°F (17.2°C).Heat index
Throughout September, the heat index is computed to be a hot 87.8°F (31°C). With ongoing exposure and activity, one might experience weariness, and heat cramps could ensue.Always consider that heat index estimations are for light winds and places in the shade. The heat index might be elevated by 15 Fahrenheit (8 Celsius) degrees due to direct sun exposure.
Note: The heat index, also known as 'feels like' or 'felt air temperature', provides an understanding of perceived warmth by combining temperature and relative humidity. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. In general, younger individuals are at greater risk than adults because they tend to sweat less. Also, having a larger skin surface to body size ratio and greater heat production due to their active behavior contribute to this danger.
Humidity
In September, the average relative humidity is 41%.Rainfall
In University Heights, in September, during 2.5 rainfall days, 0.12" (3mm) of precipitation is typically accumulated. In University Heights, during the entire year, the rain falls for 43.5 days and collects up to 5.43" (138mm) of precipitation.Snowfall
In University Heights, snow does not fall in January, March through December.Daylight
In University Heights, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:14 pm. On the last day of September, sunrise is at 6:43 am and sunset at 6:34 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In September, a daily UV index of 6 turns into the following recommendations:
Resist extreme sun exposure. Guarding against solar damage is essential. 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. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
University Heights, CA
- Average high temperature in September: 87.8°F
The warmest month (with the highest average high temperature) is August (91.9°F).
The month with the lowest average high temperature is December (59.9°F).
- Average low temperature in September: 63°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (43.3°F).
Average pressure in September
University Heights, CA
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
University Heights, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
University Heights, CA
- Average humidity in September: 41%
The months with the highest relative humidity are February and March (52%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
University Heights, CA
- Average rainfall in September: 0.12"
The wettest months (with the highest rainfall) are February and December (1.14").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
University Heights, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is December (5.5 days).
The month with the least rainy days is June (1.3 days).
Average snowfall days in September
University Heights, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
University Heights, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 42min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
University Heights, CA
- Average sunshine days in September: 24.7 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (22.6 days).
Average UV index in September
University Heights, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
University Heights, CA
- Average cloud cover in September: 6
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
University Heights, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





