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
The weather during September records an average high-temperature of a still hot 86.9°F (30.5°C), closely mirroring the preceding month. Rio Vista, in September, displays a significant temperature downturn during the night, with an average reading of 58.1°F (14.5°C).Heat index
September's heat index is computed to be a tropical 89.6°F (32°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
Humidity
With an average relative humidity of 49%, September is the least humid month.Rainfall
Months with rainfall in Rio Vista are January through July, September through December. September is the first month it rains. Throughout September, in the average 1.6 rainfall days, it receives 0.08" (2mm) of precipitation. In Rio Vista, during the entire year, the rain falls for 68.7 days and collects up to 11.18" (284mm) of precipitation.Daylight
In September, the average length of the day in Rio Vista 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 Rio Vista, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: During September, 5 as the daily maximum UV index converts into the following advice:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Frequently asked questions
How hot is September in Rio Vista?
What is the least humid month in Rio Vista?
What is the average humidity in September in Rio Vista?
When does it start to rain in Rio Vista?
How many hours of daylight does Rio Vista have in September?
When are sunrise and sunset in September in Rio Vista?
How many hours of sunshine does Rio Vista have in September?
What is the UV index reading in September in Rio Vista?
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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