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 snowfall 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
September
Weather in September
Temperature
Montclair's transition from August to September introduces an average high-temperature of a still tropical 88.2°F (31.2°C), marking an insignificant variation from the 91°F (32.8°C). Montclair observes a noteworthy temperature drop from the daily highs during September nights, with a mean temperature of 63.5°F (17.5°C).Heat index
For September, the heat index is calculated to be a hot 89.6°F (32°C). If one stays active during extended exposure, it might induce fatigue and result in heat cramps.Given the heat index, its values are aligned with shaded sites and gentle winds. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. In general, children are more at risk than adults because they sweat less. Furthermore, the large skin surface compared to their small bodies and the high heat production due to their actions contribute to this vulnerability.
Humidity
The average relative humidity in September is 44%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. Throughout the year, there are 49.6 rainfall days, and 7.8" (198mm) of precipitation is accumulated.Snowfall
In Montclair, snow does not fall in January, March through December.Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:35 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Stick with precautions and abide by sun safety procedures. Evading sunburn is essential. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
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 intensity in September?
Average temperature in September
Montclair, CA
- Average high temperature in September: 88.2°F
The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is December (62.1°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure in September
Montclair, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Montclair, 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
Montclair, CA
- Average humidity in September: 44%
The months with the highest relative humidity are March and May (54%).
The month with the lowest relative humidity is August (42%).
Average rainfall in September
Montclair, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Montclair, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in September
Montclair, 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
Montclair, 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 54min).
Average sunshine days in September
Montclair, CA
- Average sunshine days in September: 25.4 days
The month with the most sunshine days is June (28.2 days).
The month with the least sunshine days is February (21.5 days).
Average UV index in September
Montclair, 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
Montclair, CA
- Average cloud cover in September: 6
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Montclair, 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).