Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The advent of September presents an average high-temperature of a still moderately hot 81.3°F (27.4°C), maintaining a close correlation with the preceding month. The nights of September anticipate an average low-temperature of 64.8°F (18.2°C).Heat index
For most parts of September, the heat index is computed to be 84.2°F (29°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.The standards for the heat index are set for locations in shade and under light breezes. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is the outcome of merging air's temperature and its humidity metrics. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Humidity
In September, the average relative humidity is 60%.Rainfall
In September, the rain falls for 1.4 days. Throughout September, 0.04" (1mm) of precipitation is accumulated. In Cerritos, during the entire year, the rain falls for 33.3 days and collects up to 2.32" (59mm) of precipitation.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:37 pm PDT.
Sunshine
The average sunshine in September is 10.6h.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 hazard from exposure to the Sun's UV rays for average individuals.Note: In September, the maximum UV index of 6 suggests these recommendations:
Deflect overexposure. Sun protection is a necessity. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How many days does it rain in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Cerritos have in September?
When is the highest UV index?
How high is the UV index in September?
Average temperature in September
Cerritos, CA
- Average high temperature in September: 81.3°F
The warmest month (with the highest average high temperature) is August (82°F).
The month with the lowest average high temperature is December (64°F).
- Average low temperature in September: 64.8°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (51.3°F).
Average pressure in September
Cerritos, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).
Average wind speed in September
Cerritos, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest months (with the lowest average wind speed) are September and October (4.8mph).
Average humidity in September
Cerritos, CA
- Average humidity in September: 60%
The month with the highest relative humidity is June (67%).
The month with the lowest relative humidity is November (52%).
Average rainfall in September
Cerritos, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is December (0.55").
The driest month (with the least rainfall) is June (0").
Average rainfall days in September
Cerritos, CA
- Average rainfall days in September: 1.4 days
The month with the highest number of rainy days is March (5.6 days).
The month with the least rainy days is June (0.6 days).
Average daylight in September /
Average sunshine in September
Cerritos, CA
- Average daylight in September: 12h and 2min
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 4min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Cerritos, CA
- Average sunshine days in September: 26.6 days
The month with the most sunshine days is June (28.6 days).
The month with the least sunshine days is February (22.9 days).
Average UV index in September
Cerritos, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are February, November and December (UV index 4).
Average cloud cover in September
Cerritos, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Cerritos, 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).
Cerritos, California, USA
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