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 move into September indicates a slight reduction in the average high-temperature, down from August's hot 90.9°F (32.7°C) to a warm 85.3°F (29.6°C). September nights in Altaville report a substantial dip from daytime highs to an average of 58.8°F (14.9°C).Humidity
In September, the average relative humidity is 36%.Rainfall
In Altaville, in September, during 3 rainfall days, 0.24" (6mm) of precipitation is typically accumulated. In Altaville, during the entire year, the rain falls for 74.4 days and collects up to 22.87" (581mm) of precipitation.Snowfall
In Altaville, snow does not fall in April through October.Daylight
The average length of the day in September in Altaville is 12h and 25min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:46 pm PDT.
Sunshine
In Altaville, the average sunshine in September is 11.3h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The daily high UV index of 5 in September translates into this advice:
Heed the precautions - Suggestions to avoid sunburn are made. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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 average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Altaville have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Altaville have in September?
What is the UV index reading in September?
Average temperature in September
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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
Altaville, 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).
Altaville, California, USA
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