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
The commencement of September notes an average high-temperature of a still warm 82.4°F (28°C), exhibiting little difference from the previous month. With a notable disparity from daily peak temperatures, the average low-temperature in Asti settles at a fresh 52.7°F (11.5°C) throughout September.Heat index
During September, the heat index is evaluated at 84.2°F (29°C). When exposure and activity are sustained, they could induce fatigue, with a chance of heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'felt air temperature' or 'real feel', evaluates the perceived heat by adding the effect of moisture in the air. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. 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
July and September, with an average relative humidity of 57%, are the least humid months.Rainfall
In Asti, in September, during 2.2 rainfall days, 0.16" (4mm) of precipitation is typically accumulated. Throughout the year, there are 82.4 rainfall days, and 20.75" (527mm) of precipitation is accumulated.Snowfall
January, March through December are months without snowfall.Daylight
In Asti, the average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:41 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:55 pm PDT.
Sunshine
In Asti, the average sunshine in September is 10.9h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Make use of precautions - It is urged to ward off sun damage. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the least humid month?
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 in Asti?
Average temperature in September
Asti, CA
- Average high temperature in September: 82.4°F
The warmest month (with the highest average high temperature) is July (86.2°F).
The month with the lowest average high temperature is December (54.9°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is December (38.5°F).
Average pressure in September
Asti, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Asti, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is November (4.6mph).
Average humidity in September
Asti, CA
- Average humidity in September: 57%
The month with the highest relative humidity is March (77%).
The months with the lowest relative humidity are July and September (57%).
Average rainfall in September
Asti, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is February (4.25").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Asti, CA
- Average rainfall days in September: 2.2 days
The month with the highest number of rainy days is March (14.6 days).
The months with the least rainy days are July and August (1.2 days).
Average snowfall in September
Asti, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.16").
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
Asti, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.2 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Asti, 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 30min).
- Average sunshine in September: 10h and 5min
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 24min).
Average sunshine days in September
Asti, CA
- Average sunshine days in September: 27.3 days
The month with the most sunshine days is July (29.4 days).
The month with the least sunshine days is March (15.2 days).
Average UV index in September
Asti, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is November (UV index 2).
Average cloud cover in September
Asti, CA
- Average cloud cover in September: 10
The month with the most cloud cover is March (Cloud cover 43).
The months with the least cloud cover are July and August (Cloud cover 6).
Average visibility in September
Asti, 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).
Asti, California, USA
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