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
September begins with an average high-temperature of a still hot 86.2°F (30.1°C), reflecting close similarity to the preceding month. Bryn Mawr experiences a significant reduction from daytime highs with an average low-temperature of 61.7°F (16.5°C) in September.Heat index
In September, the average heat index is estimated at a hot 86°F (30°C). Prolonged activity during exposure might result in a state of fatigue and cause heat cramps.The standards for the heat index are set for locations in shade and under light breezes. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'feels like' or 'real feel', is a numerical representation of warmth when taking temperature and moisture levels into account. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Direct sun rays have a notable impact on perceived temperature, which can raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Young individuals usually face more risks than adults due to their lower sweat production. Their large skin surface area relative to their tiny bodies and high heat production from their activities adds to their risk.
Humidity
In September, the average relative humidity is 40%.Rainfall
In Bryn Mawr, in September, it is raining for 2.5 days, with typically 0.16" (4mm) of accumulated precipitation. Throughout the year, there are 49.1 rainfall days, and 6.5" (165mm) of precipitation is accumulated.Snowfall
In Bryn Mawr, snow does not fall in January, March through December.Daylight
In September, the average length of the day in Bryn Mawr, California, is 12h and 22min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:14 pm. On the last day of September, in Bryn Mawr, sunrise is at 6:43 am and sunset at 6:34 pm PDT.
Sunshine
The average sunshine in September is 10.6h.UV index
In Bryn Mawr, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation for the ordinary person.Note: A maximum high daily UV index of 6 during September translates into the following directions:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in Bryn Mawr in September?
What is the average humidity in September in Bryn Mawr?
How much does it rain in Bryn Mawr in September?
When it does not snow in Bryn Mawr?
How many hours of daylight does Bryn Mawr have in September?
What time are sunrise and sunset in September in Bryn Mawr?
How many hours of sunshine does Bryn Mawr have in September?
What is the UV index reading in September in Bryn Mawr?
Average temperature in September
Bryn Mawr, CA
- Average high temperature in September: 86.2°F
The warmest months (with the highest average high temperature) are July and August (90.3°F).
The month with the lowest average high temperature is December (58.8°F).
- Average low temperature in September: 61.7°F
The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).
Average pressure in September
Bryn Mawr, CA
- Average pressure in September: 29.86"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Bryn Mawr, CA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is April (6.3mph).
The calmest month (with the lowest average wind speed) is September (4.7mph).
Average humidity in September
Bryn Mawr, CA
- Average humidity in September: 40%
The month with the highest relative humidity is February (53%).
The month with the lowest relative humidity is August (37%).
Average rainfall in September
Bryn Mawr, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.42").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Bryn Mawr, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (6.7 days).
The month with the least rainy days is June (1.3 days).
Average snowfall days in September
Bryn Mawr, 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
Bryn Mawr, 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 12min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).
Average sunshine days in September
Bryn Mawr, CA
- Average sunshine days in September: 25.1 days
The month with the most sunshine days is June (28 days).
The month with the least sunshine days is February (21.3 days).
Average UV index in September
Bryn Mawr, CA
- Average UV index in September: 6
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Bryn Mawr, CA
- Average cloud cover in September: 6
The months with the most cloud cover are February, March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Bryn Mawr, 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).
Bryn Mawr, California, USA
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