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
September's onset brings an average high-temperature of a still moderately hot 79°F (26.1°C), showing a minute difference from August's 79.9°F (26.6°C). During the nights in September, Irvine experiences a consistent average temperature of 64.4°F (18°C).Humidity
In September, the average relative humidity is 64%.Rainfall
In Irvine, in September, during 4.1 rainfall days, 0.31" (8mm) of precipitation is typically accumulated. Throughout the year, there are 63.7 rainfall days, and 7.91" (201mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:36 pm PDT.
Sunshine
In Irvine, the average sunshine in September is 10.6h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: A daily high UV index of 6 in September leads to these guidelines:
Enforce precautions and stick to sun safety measures. Preservation from skin and eye damage is essential. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
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 in Irvine?
How many hours of daylight does Irvine have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
When is the highest UV index?
What is the UV index intensity in September in Irvine?
Average temperature in September
Irvine, CA
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is August (79.9°F).
The month with the lowest average high temperature is December (63°F).
- Average low temperature in September: 64.4°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (50.5°F).
Average pressure in September
Irvine, 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
Irvine, 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
Irvine, CA
- Average humidity in September: 64%
The month with the highest relative humidity is June (71%).
The month with the lowest relative humidity is November (56%).
Average rainfall in September
Irvine, CA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Irvine, CA
- Average rainfall days in September: 4.1 days
The month with the highest number of rainy days is March (7.9 days).
The month with the least rainy days is June (2.2 days).
Average daylight in September /
Average sunshine in September
Irvine, 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: 10h and 0min).
- 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 36min).
Average sunshine days in September
Irvine, CA
- Average sunshine days in September: 22.1 days
The month with the most sunshine days is January (24.5 days).
The month with the least sunshine days is May (19.7 days).
Average UV index in September
Irvine, 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 January, February, March, November and December (UV index 4).
Average cloud cover in September
Irvine, CA
- Average cloud cover in September: 10
The month with the most cloud cover is December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in September
Irvine, 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).
Irvine, California, USA
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