September weather forecastRancho Santa Margarita, CA
September
Weather in September
September, the first month of the autumn in Rancho Santa Margarita, is also a moderately hot month, with an average temperature varying between 63.5°F (17.5°C) and 79.7°F (26.5°C).Temperature
September's advent presents an average high-temperature of a still moderately hot 79.7°F (26.5°C), indicating a slight variation from the conditions of the previous month. In Rancho Santa Margarita, the average temperature during the nights of September drops to an enjoyable 63.5°F (17.5°C).Humidity
In September, the average relative humidity is 63%.Rainfall
In Rancho Santa Margarita, in September, during 4.5 rainfall days, 0.24" (6mm) of precipitation is typically accumulated. In Rancho Santa Margarita, during the entire year, the rain falls for 64.2 days and collects up to 5.79" (147mm) of precipitation.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:24 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:35 pm PDT.
Sunshine
The average sunshine in September is 10.5h.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 unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index of 6 during September leads to these instructions:
Fend off overexposure. Sun protection is vital. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rancho Santa Margarita, CA
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (63°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is February (48.9°F).
Average pressure in September
Rancho Santa Margarita, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.88"Hg).
Average wind speed in September
Rancho Santa Margarita, CA
- Average wind speed in September: 4.6mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Rancho Santa Margarita, CA
- Average humidity in September: 63%
The months with the highest relative humidity are May and June (70%).
The month with the lowest relative humidity is November (56%).
Average rainfall in September
Rancho Santa Margarita, CA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is December (1.02").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Rancho Santa Margarita, CA
- Average rainfall days in September: 4.5 days
The month with the highest number of rainy days is March (8.6 days).
The month with the least rainy days is June (1.9 days).
Average daylight in September /
Average sunshine in September
Rancho Santa Margarita, 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: 10h and 0min).
- Average sunshine in September: 10h and 30min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days in September
Rancho Santa Margarita, CA
- Average sunshine days in September: 22.2 days
The month with the most sunshine days is January (24.3 days).
The month with the least sunshine days is February (19.8 days).
Average UV index in September
Rancho Santa Margarita, 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
Rancho Santa Margarita, CA
- Average cloud cover in September: 11
The months with the most cloud cover are March and December (Cloud cover 25).
The month with the least cloud cover is August (Cloud cover 7).
Average visibility in September
Rancho Santa Margarita, 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).





