September weather forecastPerris, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in Perris, California, with an average temperature varying between 61.3°F (16.3°C) and 85.8°F (29.9°C).Temperature
During September, Perris records an average high-temperature of a moderately hot 85.8°F (29.9°C), marking a slight divergence from August's 89.6°F (32°C). A significant drop from the day's peak to an average low-temperature of 61.3°F (16.3°C) is noted during the nights in September.Heat index
Throughout September, the heat index is estimated at a tropical 87.8°F (31°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a composite of temperature and humidity figures to convey how warm it feels. Depending on the activity and the individual's heat perception, which may vary due to factors including wind, clothing, and metabolic variations, this effect remains subjective. Direct sunlight can potentially raise the heat index by 15 Fahrenheit (8 Celsius) degrees, so it's crucial to consider. Heat index values are highly critical to babies and toddlers. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.
Humidity
In September, the average relative humidity is 49%.Rainfall
In Perris, in September, it is raining for 3.5 days, with typically 0.2" (5mm) of accumulated precipitation. In Perris, during the entire year, the rain falls for 55.7 days and collects up to 7.05" (179mm) of precipitation.Snowfall
In Perris, snow does not fall in January, March through December.Daylight
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 7:14 pm. On the last day of the month, sunrise is at 6:43 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine is 10.6h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 6 suggests these recommendations:
Take precautions against overexposure. Protection against sun damage is needed. Between 10 a.m. and 4 p.m., UV radiation is strongest. Make an effort to avoid direct sunlight during this time, remembering that shade structures may not provide full sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Perris, CA
- Average high temperature in September: 85.8°F
The warmest month (with the highest average high temperature) is August (89.6°F).
The month with the lowest average high temperature is December (61°F).
- Average low temperature in September: 61.3°F
The month with the highest average low temperature is August (63.3°F).
The coldest month (with the lowest average low temperature) is December (43°F).
Average pressure in September
Perris, 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
Perris, CA
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest months (with the lowest average wind speed) are August and September (4.2mph).
Average humidity in September
Perris, CA
- Average humidity in September: 49%
The month with the highest relative humidity is May (60%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Perris, CA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is December (1.38").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Perris, CA
- Average rainfall days in September: 3.5 days
The month with the highest number of rainy days is March (7.2 days).
The month with the least rainy days is June (1.3 days).
Average snowfall in September
Perris, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Perris, 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
Perris, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 36min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Perris, CA
- Average sunshine days in September: 23.4 days
The month with the most sunshine days is June (26.9 days).
The month with the least sunshine days is February (21.6 days).
Average UV index in September
Perris, CA
- Average UV index in September: 6
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Perris, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Perris, 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).
