September weather forecastWest Covina, CA
September
Weather in September
September signifies the beginning of a cooling trend in West Covina. The searing heat of summer transitions into a milder climate. With declining temperatures and an increase in cloud cover, the clear summer skies give way to cloudier autumn days. Meandering through the city, you will observe the leaves begin to change color, embodying the essence of fall. The gradual decrease in heat and sunshine hours throughout September sets the tone for October's cooler climate.Temperature
The initiation of September records an average high-temperature of a moderately hot 85.8°F (29.9°C), displaying a near consistency with the previous month. In September, the temperature sees a substantial plunge from daytime highs to a low average of 63.5°F (17.5°C).Heat index
The heat index value for September is calculated to be a hot 87.8°F (31°C). Exhaustion might be the outcome of enduring exposure and continuous activity, with a risk of heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is found by incorporating humidity levels into the air temperature measurement. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. Do note, being directly under sun rays can amplify the heat you feel, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Young ones often underestimate the need for rest and rehydration. Thirst appears late in dehydration - hence, it is important to keep hydrated, particularly during prolonged physical activities.
Humidity
The average relative humidity in September is 49%.Rainfall
In West Covina, in September, during 2.8 rainfall days, 0.12" (3mm) of precipitation is typically accumulated. Throughout the year, there are 49.8 rainfall days, and 7.76" (197mm) of precipitation is accumulated.Snowfall
In West Covina, snow does not fall in January through November.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:25 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:36 pm PDT.
Sunshine
In September, the average sunshine in West Covina, California, is 10.8h.UV index
In West Covina, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for average individuals.Note: A typical high UV index of 6 in September suggests the following recommendations:
Endorse precautions and be consistent with sun safety guidelines. Preventing sunburn is paramount. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
West Covina, CA
- Average high temperature in September: 85.8°F
The warmest month (with the highest average high temperature) is August (88.9°F).
The month with the lowest average high temperature is December (63.5°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is December (47.3°F).
Average pressure in September
West Covina, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
West Covina, CA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest months (with the lowest average wind speed) are September and October (4.5mph).
Average humidity in September
West Covina, CA
- Average humidity in September: 49%
The months with the highest relative humidity are May and June (57%).
The month with the lowest relative humidity is November (46%).
Average rainfall in September
West Covina, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is December (1.73").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
West Covina, CA
- Average rainfall days in September: 2.8 days
The month with the highest number of rainy days is March (6.8 days).
The month with the least rainy days is June (1.3 days).
Average snowfall days in September
West Covina, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
West Covina, 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: 9h and 54min).
- Average sunshine in September: 10h and 48min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
West Covina, CA
- Average sunshine days in September: 25.7 days
The month with the most sunshine days is June (28 days).
The month with the least sunshine days is February (21.6 days).
Average UV index in September
West Covina, CA
- Average UV index in September: 6
The month with the highest UV index is August (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in September
West Covina, CA
- Average cloud cover in September: 7
The month with the most cloud cover is December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
West Covina, 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).
