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 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
Rio Vista registers an average high-temperature of a still tropical 86.9°F (30.5°C) at the commencement of September, closely related to the preceding month. Rio Vista documents a substantial deviation from daytime highs with a consistent low-temperature of 58.1°F (14.5°C) during September nights.Heat index
For most parts of September, the heat index is estimated at a tropical 89.6°F (32°C). Long-standing exposure and activity could induce a feeling of tiredness and lead to heat cramps.Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. The heat index can potentially augment by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. This effect is personal, shaped by the individual's physical activity and heat sensitivity, influenced by factors including wind, clothing, and metabolic variances. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children often fail to recognize the requirement to rest and rehydrate. Thirst, being a late symptom of dehydration, underlines the importance of maintaining hydration, especially during ongoing physical activities.
Humidity
The least humid month is September, with an average relative humidity of 49%.Rainfall
January through July, September through December are months with rainfall. September is the first month it rains. Throughout September, in the average 1.6 rainfall days, it receives 0.08" (2mm) of precipitation. Throughout the year, there are 68.7 rainfall days, and 11.18" (284mm) of precipitation is accumulated.Daylight
In Rio Vista, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:35 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:50 pm PDT.
Sunshine
In September, the average sunshine is 11.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Undertake protective steps - Preventing sun damage is advised. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Enhance your sun protection with tightly woven, yet airy clothing.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the least humid month?
What is the average humidity in September?
When does it start to rain?
How many hours of daylight does Rio Vista have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Rio Vista have in September?
How high is the UV index in September?
Average temperature in September
Rio Vista, CA
- Average high temperature in September: 86.9°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 58.1°F
The month with the highest average low temperature is September (58.1°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in September
Rio Vista, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Rio Vista, CA
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is June (7.6mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).
Average humidity in September
Rio Vista, CA
- Average humidity in September: 49%
The months with the highest relative humidity are January and March (74%).
The month with the lowest relative humidity is September (49%).
Average rainfall in September
Rio Vista, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.17").
The driest month (with the least rainfall) is August (0").
Average rainfall days in September
Rio Vista, CA
- Average rainfall days in September: 1.6 days
The month with the highest number of rainy days is March (13 days).
The month with the least rainy days is August (0.7 days).
Average daylight in September /
Average sunshine in September
Rio Vista, 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 1min
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
Rio Vista, CA
- Average sunshine days in September: 27.7 days
The month with the most sunshine days is August (29.9 days).
The month with the least sunshine days is March (17.3 days).
Average UV index in September
Rio Vista, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Rio Vista, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
Rio Vista, 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).
Rio Vista, California, USA
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