September weather forecastMendocino, CA
September
Weather in September
The first month of the autumn, September, is also an enjoyable month in Mendocino, California, with an average temperature varying between 54.9°F (12.7°C) and 67.5°F (19.7°C).Temperature
The highest temperatures are recorded in September, with averages reaching a high of 67.5°F (19.7°C) and a low of 54.9°F (12.7°C).Humidity
In Mendocino, the average relative humidity in September is 76%.Rainfall
In Mendocino, in September, during 2.1 rainfall days, 0.16" (4mm) of precipitation is typically accumulated. In Mendocino, during the entire year, the rain falls for 68.4 days and collects up to 9.53" (242mm) of precipitation.Snowfall
January, March through December are months without snowfall.Ocean temperature
In September, the average ocean temperature is 54.9°F (12.7°C).Note: Being in 54.9°F (12.7°C) waters at 55.4°F (13°C) is discomforting, but anything below 50°F (10°C) can jeopardize breathing and induce cold shock, factoring in physical endurance.
Daylight
In Mendocino, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:44 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 6:58 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
In Mendocino, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: A daily maximum UV index of 4 in September translates into the following instructions:
Be vigilant - A duty to shield skin and eyes from injury exists. It's recommended to limit sun exposure when its radiation is at its peak during midday. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mendocino, CA
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is September (67.5°F).
The months with the lowest average high temperature are February and December (54.3°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is February (45.5°F).
Average pressure in September
Mendocino, CA
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in September
Mendocino, CA
- Average wind speed in September: 8.3mph
The windiest month (with the highest average wind speed) is June (10.9mph).
The calmest month (with the lowest average wind speed) is August (7.8mph).
Average humidity in September
Mendocino, CA
- Average humidity in September: 76%
The months with the highest relative humidity are March, May and August (80%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Mendocino, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.77").
The driest months (with the least rainfall) are June, July and August (0.08").
Average rainfall days in September
Mendocino, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (11.4 days).
The months with the least rainy days are June and August (1.8 days).
Average snowfall in September
Mendocino, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Mendocino, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average sea temperature in September
Mendocino, CA
- Average sea temperature in September: 54.8°F
The best month for swimming (with the highest average sea temperature) is October (55.6°F).
The coldest month (with the lowest average sea temperature) is April (52.1°F).
Average daylight in September /
Average sunshine in September
Mendocino, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 10h and 42min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
Mendocino, CA
- Average sunshine days in September: 27.7 days
The month with the most sunshine days is July (28.2 days).
The month with the least sunshine days is March (18.4 days).
Average UV index in September
Mendocino, CA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Mendocino, CA
- Average cloud cover in September: 12
The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 10).
Average visibility in September
Mendocino, 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).





