September weather forecastSan Leandro, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in San Leandro, California, with an average temperature fluctuating between 77.7°F (25.4°C) and 56.5°F (13.6°C).Temperature
San Leandro witnesses its highest temperatures in July and September, reaching an average of 77.7°F (25.4°C).Humidity
The months with the lowest humidity in San Leandro are September and October, with an average relative humidity of 64%.Rainfall
The months with the least rainfall are July through September Rain falls for 1.8 days and accumulates 0.04" (1mm) of rain.Daylight
In September, the average length of the day in San Leandro is 12h and 25min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:37 pm. On the last day of September, in San Leandro, California, sunrise is at 7:04 am and sunset at 6:52 pm PDT.
Sunshine
The average sunshine in September is 11.1h.UV index
In San Leandro, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Take precautions - Protection against sun damage is advised. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Leandro, CA
- Average high temperature in September: 77.7°F
The warmest months (with the highest average high temperature) are July and September (77.7°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is September (56.5°F).
The coldest month (with the lowest average low temperature) is January (44.1°F).
Average pressure in September
San Leandro, 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
San Leandro, CA
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is May (7mph).
The calmest month (with the lowest average wind speed) is November (4.8mph).
Average humidity in September
San Leandro, CA
- Average humidity in September: 64%
The month with the highest relative humidity is March (75%).
The months with the lowest relative humidity are September and October (64%).
Average rainfall in September
San Leandro, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is February (1.26").
The driest months (with the least rainfall) are July, August and September (0.04").
Average rainfall days in September
San Leandro, CA
- Average rainfall days in September: 1.8 days
The month with the highest number of rainy days is March (10.2 days).
The month with the least rainy days is August (0.7 days).
Average daylight in September /
Average sunshine in September
San Leandro, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 6min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in September
San Leandro, CA
- Average sunshine days in September: 27 days
The month with the most sunshine days is July (27.1 days).
The month with the least sunshine days is March (19.1 days).
Average UV index in September
San Leandro, 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
San Leandro, CA
- Average cloud cover in September: 11
The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 8).
Average visibility in September
San Leandro, 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).
