Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September marks a gentle change in average high-temperature, declining from August's tropical 90.9°F (32.7°C) to a moderately hot 85.3°F (29.6°C). In September, the temperature registers a significant dip to an average of 58.8°F (14.9°C) at night.Humidity
The average relative humidity in September is 36%.Rainfall
In Vallecito, in September, it is raining for 3 days, with typically 0.24" (6mm) of accumulated precipitation. In Vallecito, during the entire year, the rain falls for 74.4 days and collects up to 22.87" (581mm) of precipitation.Snowfall
In Vallecito, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Vallecito, sunrise is at 6:32 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm PDT.
Sunshine
In September, the average sunshine is 11.3h.UV index
In Vallecito, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The UV index of 5 during September leads to these advisories:
Heed the precautions - Suggestions to avoid sunburn are made. To avoid the Sun's strongest rays, limit exposure around the mid-day period. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Vallecito, CA
- Average high temperature in September: 85.3°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is December (53.2°F).
- Average low temperature in September: 58.8°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is December (37.8°F).
Average pressure in September
Vallecito, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Vallecito, CA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is February (5.7mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).
Average humidity in September
Vallecito, CA
- Average humidity in September: 36%
The month with the highest relative humidity is March (71%).
The months with the lowest relative humidity are July and August (34%).
Average rainfall in September
Vallecito, CA
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is March (4.76").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Vallecito, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (13 days).
The month with the least rainy days is August (1.2 days).
Average snowfall in September
Vallecito, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.32").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Vallecito, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Vallecito, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 2min
The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Vallecito, CA
- Average sunshine days in September: 26.8 days
The month with the most sunshine days is July (29.1 days).
The month with the least sunshine days is March (16.8 days).
Average UV index in September
Vallecito, CA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The month with the lowest UV index is November (UV index 2).
Average cloud cover in September
Vallecito, CA
- Average cloud cover in September: 7
The month with the most cloud cover is March (Cloud cover 37).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
Vallecito, 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).
Vallecito, California, USA
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