September weather forecastRoseland, CA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Roseland, California, with an average temperature fluctuating between 79°F (26.1°C) and 54.7°F (12.6°C).Temperature
Roseland's weather, upon September's arrival, documents an average high-temperature of a still warm 79°F (26.1°C), nearly identical to the prior month. Roseland, amid September nights, sees a noteworthy disparity from daily highs with an average temperature of 54.7°F (12.6°C).Humidity
September is the least humid month, with an average relative humidity of 63%.Rainfall
In Roseland, California, during September, the rain falls for 2.8 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 72.8 rainfall days, and 12.01" (305mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:41 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:54 pm PDT.
Sunshine
In September, the average sunshine is 11h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: An average UV index of 5 in September transforms into this advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Roseland, CA
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in September: 54.7°F
The months with the highest average low temperature are August and September (54.7°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).
Average pressure in September
Roseland, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Roseland, CA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).
Average humidity in September
Roseland, CA
- Average humidity in September: 63%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (63%).
Average rainfall in September
Roseland, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (2.64").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Roseland, CA
- Average rainfall days in September: 2.8 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.8 days).
Average daylight in September /
Average sunshine in September
Roseland, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Roseland, CA
- Average sunshine days in September: 26.5 days
The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (17.1 days).
Average UV index in September
Roseland, CA
- Average UV index in September: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Roseland, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Roseland, 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).





