September weather forecastPorterville, CA
September
Weather in September
September, the first month of the autumn in Porterville, is still a tropical month, with temperature in the range of an average high of 90.7°F (32.6°C) and an average low of 61.9°F (16.6°C).Temperature
The transition into September involves a small decrease in the average high-temperature, dipping slightly from a fiery hot 96.8°F (36°C) in August to a hot 90.7°F (32.6°C). The nighttime average for Porterville in September plummets considerably from its daytime counterpart, resting at a comfortable 61.9°F (16.6°C).Humidity
In September, the average relative humidity is 32%.Rainfall
In September, the rain falls for 1.5 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. Throughout the year, there are 52.3 rainfall days, and 9.37" (238mm) of precipitation is accumulated.Snowfall
In Porterville, snow does not fall in January, March through December.Daylight
In Porterville, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 6:28 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:40 pm PDT.
Sunshine
The average sunshine in September is 11h.UV index
In Porterville, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 6 in September translates into this advice:
Avoid excessive sunlight. Those with lighter skin may experience burning in less than 20 minutes. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Porterville, CA
- Average high temperature in September: 90.7°F
The warmest month (with the highest average high temperature) is July (97.7°F).
The month with the lowest average high temperature is December (57.6°F).
- Average low temperature in September: 61.9°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is December (40.3°F).
Average pressure in September
Porterville, CA
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Porterville, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is June (5.2mph).
The calmest month (with the lowest average wind speed) is December (3.6mph).
Average humidity in September
Porterville, CA
- Average humidity in September: 32%
The month with the highest relative humidity is January (64%).
The month with the lowest relative humidity is August (30%).
Average rainfall in September
Porterville, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is March (1.93").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in September
Porterville, CA
- Average rainfall days in September: 1.5 days
The month with the highest number of rainy days is March (9.3 days).
The month with the least rainy days is August (0.5 days).
Average snowfall days in September
Porterville, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.2 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
Porterville, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 11h and 0min
The months with the most sunshine are June and July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).
Average sunshine days in September
Porterville, CA
- Average sunshine days in September: 27.7 days
The month with the most sunshine days is August (28.8 days).
The month with the least sunshine days is February (20.3 days).
Average UV index in September
Porterville, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 3).
Average cloud cover in September
Porterville, CA
- Average cloud cover in September: 5
The month with the most cloud cover is March (Cloud cover 24).
The months with the least cloud cover are July and August (Cloud cover 4).
Average visibility in September
Porterville, 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).
