September weather forecastSimi Valley, CA
September
Weather in September
September, the first month of the autumn in Simi Valley, is still a warm month, with temperature in the range of an average low of 62.1°F (16.7°C) and an average high of 79.7°F (26.5°C).Temperature
During September, the average high-temperature is a still warm 79.7°F (26.5°C), maintaining a close resemblance to that of the preceding month. The average temperature drops to an enjoyable 62.1°F (16.7°C) during the night in the month of September.Humidity
In Simi Valley, the average relative humidity in September is 55%.Rainfall
In Simi Valley, California, during September, the rain falls for 2.7 days and regularly aggregates up to 0.2" (5mm) of precipitation. In Simi Valley, California, during the entire year, the rain falls for 53.7 days and collects up to 9.61" (244mm) of precipitation.Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:20 pm. On the last day of September, in Simi Valley, sunrise is at 6:49 am and sunset at 6:40 pm PDT.
Sunshine
In September, the average sunshine is 10.9h.UV index
In Simi Valley, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In September, an average UV index of 5 transforms into the following instructions:
Adopt protective measures - It is advised to guard against sun damage. Around midday, solar radiation is most harmful; hence, exposure should be limited. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Simi Valley, CA
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is August (82.2°F).
The month with the lowest average high temperature is December (60.1°F).
- Average low temperature in September: 62.1°F
The month with the highest average low temperature is August (63.1°F).
The coldest month (with the lowest average low temperature) is December (46.4°F).
Average pressure in September
Simi Valley, CA
- Average pressure in September: 29.9"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are June and September (29.9"Hg).
Average wind speed in September
Simi Valley, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is December (6.5mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in September
Simi Valley, CA
- Average humidity in September: 55%
The month with the highest relative humidity is June (62%).
The month with the lowest relative humidity is November (50%).
Average rainfall in September
Simi Valley, CA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is February (1.93").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Simi Valley, CA
- Average rainfall days in September: 2.7 days
The month with the highest number of rainy days is March (8 days).
The months with the least rainy days are June and August (1.5 days).
Average daylight in September /
Average sunshine in September
Simi Valley, 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 54min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 48min).
Average sunshine days in September
Simi Valley, CA
- Average sunshine days in September: 23.5 days
The month with the most sunshine days is August (25.4 days).
The month with the least sunshine days is February (20.9 days).
Average UV index in September
Simi Valley, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Simi Valley, CA
- Average cloud cover in September: 7
The month with the most cloud cover is March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Simi Valley, 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).
