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
Whittier notes an average high-temperature of a moderately hot 85.1°F (29.5°C) in September, hardly diverging from August. September's nights observe an average temperature of 64.8°F (18.2°C).Heat index
During September, the heat index is evaluated at a hot 87.8°F (31°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.Keep in mind the heat index values are meant for areas in shade and with light wind. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is a metric representing the sensation of warmth when air temperature and moisture come together. Elements of metabolic variation, physical activity, and clothing contribute to the effect of temperature on an individual. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
Humidity
In September, the average relative humidity in Whittier, California, is 53%.Rainfall
In September, in Whittier, the rain falls for 2.3 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Whittier, California, during the entire year, the rain falls for 38.2 days and collects up to 5.28" (134mm) 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
In September, the average sunshine is 10.6h.UV index
In Whittier, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV radiation for average individuals.Note: A daily high UV index of 6 in September leads to these guidelines:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in Whittier in September?
What is the average humidity in September in Whittier?
How many days does it rain in September in Whittier?
What is the average length of the day in September in Whittier?
When are sunrise and sunset in September in Whittier?
How many hours of sunshine does Whittier have in September?
How high is the UV index in September in Whittier?
Average temperature in September
Whittier, CA
- Average high temperature in September: 85.1°F
The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (64.9°F).
- Average low temperature in September: 64.8°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 (49.8°F).
Average pressure in September
Whittier, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Whittier, CA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is April (6mph).
The calmest months (with the lowest average wind speed) are September and October (4.7mph).
Average humidity in September
Whittier, CA
- Average humidity in September: 53%
The month with the highest relative humidity is June (62%).
The month with the lowest relative humidity is November (47%).
Average rainfall in September
Whittier, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is December (1.14").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Whittier, CA
- Average rainfall days in September: 2.3 days
The month with the highest number of rainy days is March (5.1 days).
The month with the least rainy days is June (1 days).
Average daylight in September /
Average sunshine in September
Whittier, 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 February (Average sunshine: 6h and 42min).
Average sunshine days in September
Whittier, CA
- Average sunshine days in September: 25.5 days
The month with the most sunshine days is June (27.9 days).
The month with the least sunshine days is February (22.6 days).
Average UV index in September
Whittier, CA
- Average UV index in September: 6
The month with the highest UV index is August (UV index 7).
The months with the lowest UV index are February, November and December (UV index 4).
Average cloud cover in September
Whittier, 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
Whittier, 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).
Whittier, California, USA
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