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
Weather in September
Temperature
The advent of September presents an average high-temperature of a still tropical 87.6°F (30.9°C), maintaining a close correlation with the preceding month. A noticeable temperature swing characterizes Claremont's September nights, dipping to an average of 64°F (17.8°C).Heat index
September's average heat index is computed to be a hot 89.6°F (32°C). With sustained exposure and activity, exhaustion becomes probable, resulting in heat cramps.Heat index values are typically calculated for conditions of shade and a light breeze. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'apparent temperature' or 'real feel', unifies temperature and humidity readings to offer a comprehensive feel of warmth. The impression of weather on a person can be swayed by additional aspects, including metabolic variations, pregnancy, and activity levels. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young ones generally face higher dangers than adults since they sweat less. Along with their large skin surface area compared totheir small bodies and increased heat production from their activities, the risks are heightened.
Humidity
In September, the average relative humidity is 46%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Claremont, during the entire year, the rain falls for 48 days and collects up to 7.52" (191mm) of precipitation.Snowfall
In Claremont, snow does not fall in January, March through December.Daylight
In Claremont, California, the average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:24 am and sunset at 7:16 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:35 pm PDT.
Sunshine
The average sunshine in September is 10.8h.UV index
In Claremont, California, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for average individuals.Note: A maximum high UV index of 6 in September translates into the following recommendations:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. 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. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
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 many days does it rain in September?
When it does not snow?
What is the average length of the day in September in Claremont?
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
Claremont, CA
- Average high temperature in September: 87.6°F
The warmest month (with the highest average high temperature) is August (90.1°F).
The month with the lowest average high temperature is December (63.1°F).
- Average low temperature in September: 64°F
The month with the highest average low temperature is August (65.7°F).
The coldest months (with the lowest average low temperature) are February and December (46.8°F).
Average pressure in September
Claremont, 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 (29.87"Hg).
Average wind speed in September
Claremont, CA
- Average wind speed in September: 4.4mph
The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in September
Claremont, CA
- Average humidity in September: 46%
The month with the highest relative humidity is May (56%).
The months with the lowest relative humidity are August and November (45%).
Average rainfall in September
Claremont, CA
- Average rainfall in September: 0.08"
The wettest months (with the highest rainfall) are February and December (1.65").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in September
Claremont, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (0.8 days).
Average snowfall days in September
Claremont, 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
Claremont, 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 5min
The month with the most sunshine is July (Average sunshine: 12h and 12min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
Claremont, CA
- Average sunshine days in September: 26.5 days
The month with the most sunshine days is June (28.7 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in September
Claremont, 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
Claremont, CA
- Average cloud cover in September: 7
The months with the most cloud cover are February, March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Claremont, 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).
Claremont, California, USA
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