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 onset of September manifests an average high-temperature of a warm 83.3°F (28.5°C), demonstrating a minor variation from the preceding month. September generally records an average low-temperature of 63.1°F (17.3°C).Heat index
The heat index for September is evaluated at 84.2°F (29°C). Long-lasting exposure and activity potentially induce a sense of weariness, with the risk of heat cramps.Bear in mind that the heat index values are determined for shaded areas and light breezes. The heat index has the possibility to be enhanced by 15 Fahrenheit (8 Celsius) degrees when there is direct sun exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is found by incorporating humidity levels into the air temperature measurement. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. Being under direct sunshine can magnify the heat experience, possibly pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Young ones often do not realize the necessity to rest and replenish their fluids. Thirst is a delayed indication of dehydration - keeping hydrated, particularly in prolonged physical activity, is crucial.
Humidity
In Sun Valley, the average relative humidity in September is 51%.Rainfall
In Sun Valley, in September, it is raining for 2.7 days, with typically 0.16" (4mm) of accumulated precipitation. Throughout the year, there are 40.1 rainfall days, and 5.87" (149mm) of precipitation is accumulated.Daylight
In Sun Valley, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:19 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:38 pm PDT.
Sunshine
The average sunshine in September is 10.8h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for average individuals.Note: The daily high UV index of 6 during September translates into the following recommendations:
Embrace precautions and observe sun safety norms. Evasion of sunburn is a necessity. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How many days does it rain in September?
How many hours of daylight does Sun Valley have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
When is the highest UV index in Sun Valley?
What is the UV index reading in September?
Average temperature in September
Sun Valley, CA
- Average high temperature in September: 83.3°F
The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (61.7°F).
- Average low temperature in September: 63.1°F
The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (46.2°F).
Average pressure in September
Sun Valley, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Sun Valley, CA
- Average wind speed in September: 4.4mph
The windiest month (with the highest average wind speed) is April (5.9mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in September
Sun Valley, CA
- Average humidity in September: 51%
The month with the highest relative humidity is June (59%).
The month with the lowest relative humidity is November (48%).
Average rainfall in September
Sun Valley, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.18").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Sun Valley, CA
- Average rainfall days in September: 2.7 days
The month with the highest number of rainy days is March (5.2 days).
The month with the least rainy days is June (1 days).
Average daylight in September /
Average sunshine in September
Sun Valley, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 5min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
Sun Valley, CA
- Average sunshine days in September: 25 days
The month with the most sunshine days is October (27.1 days).
The month with the least sunshine days is February (22.9 days).
Average UV index in September
Sun Valley, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Sun Valley, CA
- Average cloud cover in September: 6
The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Sun Valley, 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).
Sun Valley, California, USA
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