September weather forecastGlendora, CA

September
Weather in September
September, the first month of the autumn in Glendora, is also a hot month, with an average temperature varying between 86.2°F (30.1°C) and 63.5°F (17.5°C).Temperature
In September, Glendora notes an average high-temperature of a still hot 86.2°F (30.1°C), hardly different from the preceding month. A marked drop from daytime peak temperatures to an average low-temperature of 63.5°F (17.5°C) is observed during the nights in September.Heat index
September's average heat index is computed to be a hot 87.8°F (31°C). Long-lasting exposure and activity potentially induce a sense of weariness, with the risk of heat cramps.Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a metric representing the sensation of warmth when air temperature and moisture come together. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Kids generally face higher risks than adults as they sweat less. Along with their large skin surface compared to their small bodies and higher heat production due to their activities, their vulnerability is increased.
Humidity
The average relative humidity in September is 46%.Rainfall
In Glendora, in September, it is raining for 2.2 days, with typically 0.12" (3mm) of accumulated precipitation. Throughout the year, in Glendora, there are 44.9 rainfall days, and 7.76" (197mm) of precipitation is accumulated.Snowfall
January, March through December are months without snowfall in Glendora.Daylight
In Glendora, the average length of the day in September is 12h and 22min.On the first day of September in Glendora, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:36 pm PDT.
Sunshine
In September, the average sunshine in Glendora is 10.8h.UV index
In September, the average daily maximum UV index in Glendora, California, is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the maximum UV index of 6 suggests these recommendations:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun 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
Glendora, CA
- Average high temperature in September: 86.2°F
The warmest month (with the highest average high temperature) is August (88.7°F).
The month with the lowest average high temperature is December (61.5°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure in September
Glendora, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Glendora, CA
- Average wind speed in September: 4.4mph
The windiest months (with the highest average wind speed) are April and May (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in September
Glendora, CA
- Average humidity in September: 46%
The months with the highest relative humidity are March and May (55%).
The months with the lowest relative humidity are August and November (45%).
Average rainfall in September
Glendora, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.73").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Glendora, CA
- Average rainfall days in September: 2.2 days
The month with the highest number of rainy days is March (7.2 days).
The month with the least rainy days is June (1.1 days).
Average snowfall days in September
Glendora, 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
Glendora, 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 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 54min).
Average sunshine days in September
Glendora, CA
- Average sunshine days in September: 26.7 days
The month with the most sunshine days is June (28.6 days).
The month with the least sunshine days is February (22.6 days).
Average UV index in September
Glendora, 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
Glendora, CA
- Average cloud cover in September: 6
The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Glendora, 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).





