September weather forecastSan Gregorio, CA
September
Weather in September
September, the first month of the autumn in San Gregorio, is also an agreeable month, with an average temperature fluctuating between 56.7°F (13.7°C) and 72.5°F (22.5°C).Temperature
September's commencement is accompanied by an average high-temperature of a still pleasant 72.5°F (22.5°C), diverging marginally from August's 73°F (22.8°C). An average low-temperature of 56.7°F (13.7°C) is common during the nights of September.Humidity
In San Gregorio, the average relative humidity in September is 71%.Rainfall
In San Gregorio, in September, it is raining for 2.4 days, with typically 0.08" (2mm) of accumulated precipitation. Throughout the year, there are 57.5 rainfall days, and 4.76" (121mm) of precipitation is accumulated.Daylight
In San Gregorio, the average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:40 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:53 pm PDT.
Sunshine
The average sunshine in September is 11h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average UV index of 5 in September transforms into this advice:
Be vigilant - Preventing sunburn is recommended. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Gregorio, CA
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is August (73°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in September: 56.7°F
The months with the highest average low temperature are August and September (56.7°F).
The coldest months (with the lowest average low temperature) are January and February (46.4°F).
Average pressure in September
San Gregorio, 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
San Gregorio, CA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in September
San Gregorio, CA
- Average humidity in September: 71%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
San Gregorio, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (0.98").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
San Gregorio, CA
- Average rainfall days in September: 2.4 days
The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is June (0.9 days).
Average daylight in September /
Average sunshine in September
San Gregorio, 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 0min
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 Gregorio, CA
- Average sunshine days in September: 25.8 days
The months with the most sunshine days are June and July (26.3 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in September
San Gregorio, CA
- Average UV index in September: 5
The months with the highest UV index are 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
San Gregorio, CA
- Average cloud cover in September: 12
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
San Gregorio, 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).





