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 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 Fontana steps into September, the average high-temperature is measured at a still tropical 88.3°F (31.3°C), displaying minor differences from August's 92.1°F (33.4°C). The anticipated average low-temperature for September, an enjoyable 63.9°F (17.7°C), shows a substantial deviation from the daytime maximums.Heat index
For most parts of September, the heat index is calculated to be a hot 89.6°F (32°C). If one endures exposure and continues to be active, it might result in tiredness and heat cramps.In terms of the heat index, values are set with light wind and shade conditions in mind. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is the outcome of merging air's temperature and its humidity metrics. The influence of weather can be personal, changing with an individual's body mass, height, and level of physical exertion. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.
Humidity
In September, the average relative humidity is 42%.Rainfall
In Fontana, California, during September, the rain falls for 2.4 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 48.1 rainfall days, and 6.89" (175mm) of precipitation is accumulated.Snowfall
January, March through December are months without snowfall.Daylight
In Fontana, California, the average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:23 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:34 pm PDT.
Sunshine
In Fontana, the average sunshine in September is 10.7h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 6 during September leads to these advisories:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it 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 Fontana have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Fontana, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is August (92.1°F).
The month with the lowest average high temperature is December (60.8°F).
- Average low temperature in September: 63.9°F
The month with the highest average low temperature is August (67.3°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in September
Fontana, CA
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Fontana, CA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Fontana, CA
- Average humidity in September: 42%
The months with the highest relative humidity are February, March and May (52%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Fontana, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.57").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Fontana, CA
- Average rainfall days in September: 2.4 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in September
Fontana, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 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
Fontana, 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 4min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
Fontana, CA
- Average sunshine days in September: 25.9 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in September
Fontana, CA
- Average UV index in September: 6
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Fontana, CA
- Average cloud cover in September: 6
The months with the most cloud cover are February, March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Fontana, 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).
Fontana, California, USA
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