September weather forecastKnowles, CA
September
Weather in September
September, the first month of the autumn in Knowles, is also a moderately hot month, with an average temperature ranging between min 54.7°F (12.6°C) and max 81°F (27.2°C).Temperature
The advent of September brings a subtle shift in temperature, with the average high moving from a hot 86.5°F (30.3°C) in August to a moderately hot 81°F (27.2°C). Knowles registers a prominent dip from daytime highs, with an average of 54.7°F (12.6°C) during the nights of September.Humidity
In Knowles, the average relative humidity in September is 35%.Rainfall
In Knowles, in September, it is raining for 3 days, with typically 0.28" (7mm) of accumulated precipitation. In Knowles, during the entire year, the rain falls for 73.5 days and collects up to 19.69" (500mm) of precipitation.Snowfall
In Knowles, snow does not fall in May through October.Daylight
In September, the average length of the day in Knowles is 12h and 24min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:27 pm. On the last day of September, in Knowles, sunrise is at 6:54 am and sunset at 6:43 pm PDT.
Sunshine
In Knowles, the average sunshine in September is 11.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. To protect against the Sun's most potent rays, avoid direct exposure around midday. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Knowles, CA
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is July (88.2°F).
The month with the lowest average high temperature is December (48.9°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (58.8°F).
The coldest months (with the lowest average low temperature) are February and December (32.9°F).
Average pressure in September
Knowles, 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 (29.9"Hg).
Average wind speed in September
Knowles, CA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is March (5.2mph).
The calmest months (with the lowest average wind speed) are November and December (4.3mph).
Average humidity in September
Knowles, CA
- Average humidity in September: 35%
The month with the highest relative humidity is March (69%).
The months with the lowest relative humidity are July and August (32%).
Average rainfall in September
Knowles, CA
- Average rainfall in September: 0.28"
The wettest month (with the highest rainfall) is February (3.54").
The driest month (with the least rainfall) is August (0.12").
Average rainfall days in September
Knowles, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (11.3 days).
The month with the least rainy days is August (2.1 days).
Average snowfall in September
Knowles, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.55").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Knowles, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Knowles, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 12min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is February (Average sunshine: 6h and 12min).
Average sunshine days in September
Knowles, CA
- Average sunshine days in September: 25.2 days
The months with the most sunshine days are August and October (26.5 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in September
Knowles, CA
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are February, November and December (UV index 2).
Average cloud cover in September
Knowles, CA
- Average cloud cover in September: 7
The month with the most cloud cover is March (Cloud cover 31).
The months with the least cloud cover are July and August (Cloud cover 5).
Average visibility in September
Knowles, 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).





