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
During the shift to September, a minor reduction in average high-temperature is observed, shifting from a warm 84.9°F (29.4°C) in August to a still moderately hot 79.3°F (26.3°C). Despite the hot September days, Arnold's nights see an average temperature plunge to a cool 53.4°F (11.9°C).Humidity
In Arnold, California, the average relative humidity in September is 39%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.2" (5mm) of precipitation is accumulated. In Arnold, during the entire year, the rain falls for 69 days and collects up to 29.09" (739mm) of precipitation.Snowfall
In Arnold, snow does not fall in June through September.Daylight
In Arnold, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:45 pm PDT.
Sunshine
In Arnold, the average sunshine in September is 11.3h.UV index
In September, the average daily maximum UV index in Arnold is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The maximum UV index of 4 during September translates into these guidelines:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Stay sun-safe with clothing that is both closely woven and worn loosely. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Frequently asked questions
What is the usual temperature for Arnold in September?
What is the average humidity in September in Arnold?
How many days does it rain in September in Arnold?
When it does not snow in Arnold?
Does it snow in Arnold in September?
What is the average length of the day in September in Arnold?
When is the sunrise / sunset in September in Arnold?
How many hours of sunshine does Arnold have in September?
How high is the UV index in September in Arnold?
Average temperature in September
Arnold, CA
- Average high temperature in September: 79.3°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is December (48°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is December (32°F).
Average pressure in September
Arnold, 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
Arnold, CA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is February (6.1mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Arnold, CA
- Average humidity in September: 39%
The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is July (36%).
Average rainfall in September
Arnold, CA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is March (5.98").
The driest months (with the least rainfall) are July and August (0.08").
Average rainfall days in September
Arnold, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (11.3 days).
The month with the least rainy days is August (1.6 days).
Average snowfall in September
Arnold, CA
- Average snowfall in September: 0"
The month with the highest snowfall is March (21.34").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Arnold, CA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is March (7.2 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Arnold, 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: 6h and 0min).
Average sunshine days in September
Arnold, CA
- Average sunshine days in September: 26.2 days
The month with the most sunshine days is August (27.9 days).
The month with the least sunshine days is March (14.5 days).
Average UV index in September
Arnold, CA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are February, November and December (UV index 2).
Average cloud cover in September
Arnold, CA
- Average cloud cover in September: 7
The month with the most cloud cover is March (Cloud cover 37).
The months with the least cloud cover are July and August (Cloud cover 5).
Average visibility in September
Arnold, 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).
Arnold, California, USA
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