September weather forecastSan Lorenzo, CA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in San Lorenzo, California, with an average temperature fluctuating between 56.5°F (13.6°C) and 78.3°F (25.7°C).Temperature
San Lorenzo registers an average high-temperature of a still warm 78.3°F (25.7°C) with the arrival of September, showing minor deviation from the preceding month. San Lorenzo registers a pronounced decline from daytime peak temperatures, averaging a mild 56.5°F (13.6°C) lows in September.Humidity
September is the least humid month, with an average relative humidity of 62%.Rainfall
In San Lorenzo, during September, the rain falls for 2.1 days and regularly aggregates up to 0.08" (2mm) of precipitation. In San Lorenzo, during the entire year, the rain falls for 56.9 days and collects up to 4.06" (103mm) of precipitation.Daylight
The average length of the day in September 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, sunrise is at 7:03 am and sunset at 6:52 pm PDT.
Sunshine
In September, the average sunshine is 11.1h.UV index
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 the ordinary person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Be vigilant - Preventing sunburn is recommended. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Lorenzo, CA
- Average high temperature in September: 78.3°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is December (56.1°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is September (56.5°F).
The coldest months (with the lowest average low temperature) are January and December (44.1°F).
Average pressure in September
San Lorenzo, 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 Lorenzo, CA
- Average wind speed in September: 5.1mph
The windiest month (with the highest average wind speed) is May (6.7mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).
Average humidity in September
San Lorenzo, CA
- Average humidity in September: 62%
The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (62%).
Average rainfall in September
San Lorenzo, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July and August (0.04").
Average rainfall days in September
San Lorenzo, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (10.5 days).
The month with the least rainy days is August (0.7 days).
Average daylight in September /
Average sunshine in September
San Lorenzo, 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 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in September
San Lorenzo, CA
- Average sunshine days in September: 26.9 days
The month with the most sunshine days is July (27.9 days).
The month with the least sunshine days is March (18.6 days).
Average UV index in September
San Lorenzo, 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 Lorenzo, 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 7).
Average visibility in September
San Lorenzo, 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).
