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
Shifting into September, Fontana records an average high-temperature of a still hot 88.3°F (31.3°C), presenting minor fluctuations compared to the previous month. September in Fontana is characterized by a distinct thermal shift, with nighttime lows averaging at a refreshing 63.9°F (17.7°C).Heat index
Throughout September, the heat index is calculated to be a hot 89.6°F (32°C). Staying active during long-term exposure might result in a state of exhaustion and cause heat cramps.Research indicates the heat index considers values in shaded locales and with light winds. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', arises from combining readings of air temperature and relative moisture content. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Being under direct sunshine can magnify the heat experience, possibly pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Humidity
The average relative humidity in September is 42%.Rainfall
In Fontana, during September, the rain falls for 2.4 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, in Fontana, 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 the month, sunrise is at 6:23 am and sunset at 7:15 pm. On the last day of September, in Fontana, sunrise is at 6:44 am and sunset at 6:34 pm PDT.
Sunshine
In Fontana, California, the average sunshine in September is 10.7h.UV index
In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the ordinary person.Note: A maximum daily UV index of 6 during September morphs into the following directions:
Deflect overexposure. Sun protection is a necessity. Seek shade and limit direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Keep in mind that shade structures like parasols or canopies do not offer complete sun protection. 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.
Frequently asked questions
How hot is September in Fontana?
What is the average humidity in September in Fontana?
How much does it rain in Fontana in September?
When it does not snow in Fontana?
What is the average length of the day in September in Fontana?
When are sunrise and sunset in September in Fontana?
How many hours of sunshine does Fontana have in September?
What is the UV index intensity in September in Fontana?
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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