Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September registers an average high-temperature of a still hot 86°F (30°C), slightly varied from August's 88.3°F (31.3°C). Rowland Heights in September anticipates an average nighttime temperature of 64.8°F (18.2°C).Heat index
Throughout September, the heat index is calculated to be a tropical 87.8°F (31°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.Records show heat index calculations are tailored for shaded regions and mild winds. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
In Rowland Heights, the average relative humidity in September is 51%.Rainfall
In Rowland Heights, in September, during 2.1 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. Throughout the year, there are 43.8 rainfall days, and 7.01" (178mm) of precipitation is accumulated.Daylight
The average length of the day in September in Rowland Heights is 12h and 22min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of September, in Rowland Heights, sunrise is at 6:45 am and sunset at 6:36 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 health risk from exposure to the Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 6 suggests this advice:
Stay clear of intense sun exposure. Solar protection is of utmost significance. 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. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September?
How much does it rain in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Rowland Heights, CA
- Average high temperature in September: 86°F
The warmest month (with the highest average high temperature) is August (88.3°F).
The month with the lowest average high temperature is December (64.9°F).
- Average low temperature in September: 64.8°F
The month with the highest average low temperature is August (66.2°F).
The coldest month (with the lowest average low temperature) is February (48.9°F).
Average pressure in September
Rowland Heights, 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
Rowland Heights, CA
- Average wind speed in September: 4.6mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).
Average humidity in September
Rowland Heights, CA
- Average humidity in September: 51%
The month with the highest relative humidity is June (59%).
The month with the lowest relative humidity is November (46%).
Average rainfall in September
Rowland Heights, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is December (1.61").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in September
Rowland Heights, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (6.6 days).
The month with the least rainy days is June (1.1 days).
Average daylight in September /
Average sunshine in September
Rowland Heights, CA
- Average daylight in September: 12h and 2min
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 4min
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 48min).
Average sunshine days in September
Rowland Heights, CA
- Average sunshine days in September: 26.1 days
The month with the most sunshine days is August (28.2 days).
The month with the least sunshine days is February (21.6 days).
Average UV index in September
Rowland Heights, 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
Rowland Heights, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Rowland Heights, 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).
Rowland Heights, California, USA
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