September weather forecastLas Lomas, CA
September
Weather in September
September, the first month of the autumn in Las Lomas, is also a moderately hot month, with an average temperature ranging between max 77.9°F (25.5°C) and min 54.9°F (12.7°C).Temperature
September reports an average high-temperature of a still warm 77.9°F (25.5°C), slightly varied from August's 78.1°F (25.6°C). September nights experience a distinct temperature drop from the daily highs, with an average low-temperature of 54.9°F (12.7°C).Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 65%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. Throughout the year, there are 68.3 rainfall days, and 11.38" (289mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 24min.On the first day of September, sunrise is at 6:38 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.
Sunshine
In September, the average sunshine is 11.3h.UV index
April, June through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum daily UV index, 5 in September, converts into the following recommendations:
Act with care - The need to guard against sun damage is communicated. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Las Lomas, CA
- Average high temperature in September: 77.9°F
The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is December (57.9°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is September (54.9°F).
The coldest month (with the lowest average low temperature) is February (43.3°F).
Average pressure in September
Las Lomas, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in September
Las Lomas, CA
- Average wind speed in September: 4.7mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest months (with the lowest average wind speed) are January, August, September, October and November (4.7mph).
Average humidity in September
Las Lomas, CA
- Average humidity in September: 65%
The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (65%).
Average rainfall in September
Las Lomas, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is December (2.13").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Las Lomas, CA
- Average rainfall days in September: 2.5 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
Las Lomas, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 18min
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 0min).
Average sunshine days in September
Las Lomas, CA
- Average sunshine days in September: 27 days
The month with the most sunshine days is August (29.3 days).
The month with the least sunshine days is March (17.6 days).
Average UV index in September
Las Lomas, CA
- Average UV index in September: 5
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in September
Las Lomas, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Las Lomas, 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).
