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
As Alpine steps into September, the average high-temperature holds at a moderately hot 84.2°F (29°C), hinting at a minor fluctuation from the prior month. Alpine observes an average low-temperature of 62.8°F (17.1°C) during September.Heat index
Throughout September, the heat index is evaluated at a hot 86°F (30°C). Ongoing activity coupled with exposure often results in weariness and could induce heat cramps.Heat index values are typically calculated for conditions of shade and a light breeze. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is a value derived by merging air temperature with the humidity to convey how the climate feels. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Kids generally face higher risks than adults as they sweat less. Along with their large skin surface compared to their small bodies and higher heat production due to their activities, their vulnerability is increased.
Humidity
In September, the average relative humidity is 53%.Rainfall
In Alpine, California, in September, during 5.5 rainfall days, 0.51" (13mm) of precipitation is typically accumulated. Throughout the year, in Alpine, there are 62 rainfall days, and 6.38" (162mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 22min.On the first day of September, sunrise is at 6:22 am and sunset at 7:11 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:32 pm PDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, a daily UV index of 6 turns into the following recommendations:
Ward off overexposure. Defence against solar harm is crucial. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Frequently asked questions
How hot does it get in Alpine in September?
What is the average humidity in September in Alpine?
How much does it rain in Alpine in September?
How many hours of daylight does Alpine have in September?
What time are sunrise and sunset in September in Alpine?
How many hours of sunshine does Alpine have in September?
When is the highest UV index in Alpine?
What is the UV index reading in September in Alpine?
Average temperature in September
Alpine, CA
- Average high temperature in September: 84.2°F
The warmest month (with the highest average high temperature) is August (87.3°F).
The month with the lowest average high temperature is December (61.3°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (44.2°F).
Average pressure in September
Alpine, CA
- Average pressure in September: 29.86"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Alpine, CA
- Average wind speed in September: 4.1mph
The windiest month (with the highest average wind speed) is May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.1mph).
Average humidity in September
Alpine, CA
- Average humidity in September: 53%
The month with the highest relative humidity is May (62%).
The month with the lowest relative humidity is November (51%).
Average rainfall in September
Alpine, CA
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is February (0.94").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Alpine, CA
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (1.5 days).
Average daylight in September /
Average sunshine in September
Alpine, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 2min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Alpine, CA
- Average sunshine days in September: 21.8 days
The month with the most sunshine days is June (27.5 days).
The month with the least sunshine days is July (19.4 days).
Average UV index in September
Alpine, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are November and December (UV index 3).
Average cloud cover in September
Alpine, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Alpine, 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).
Alpine, California, USA
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