September weather forecastBristol, ME
September
Weather in September
September, the first month of the autumn in Bristol, is also an enjoyable month, with an average temperature varying between 53.6°F (12°C) and 67.5°F (19.7°C).Temperature
September is marked by a subtle drop in average high-temperatures, transitioning from a warm 74.1°F (23.4°C) in August to a comfortable 67.5°F (19.7°C). Bristol observes an average nighttime low-temperature of 53.6°F (12°C) during the month of September.Humidity
In September, the average relative humidity is 80%.Rainfall
September is the month with the least rainfall. Rain falls for 10.8 days and accumulates 1.5" (38mm) of precipitation.Snowfall
In Bristol, snow does not fall in June through October.Daylight
In Bristol, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:02 am and sunset at 7:13 pm. On the last day of September, sunrise is at 6:35 am and sunset at 6:20 pm EDT.
Sunshine
In Bristol, the average sunshine in September is 8.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, a regular UV index of 4 translates into these guidelines:
Take precautions - Protection against sun damage is advised. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. 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
Average temperature in September
Bristol, ME
- Average high temperature in September: 67.5°F
The warmest months (with the highest average high temperature) are July and August (74.1°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 53.6°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Bristol, ME
- Average pressure in September: 30.04"Hg
The months with the highest atmospheric pressure are September and November (30.04"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Bristol, ME
- Average wind speed in September: 7.5mph
The windiest months (with the highest average wind speed) are January and March (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Bristol, ME
- Average humidity in September: 80%
The months with the highest relative humidity are June and July (82%).
The month with the lowest relative humidity is November (76%).
Average rainfall in September
Bristol, ME
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is December (3.5").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in September
Bristol, ME
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is April (15.1 days).
The month with the least rainy days is January (6.6 days).
Average snowfall in September
Bristol, ME
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.28").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Bristol, ME
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Bristol, ME
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 24min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The months with the least sunshine are February and December (Average sunshine: 4h and 36min).
Average sunshine days in September
Bristol, ME
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is September (17.5 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in September
Bristol, ME
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Bristol, ME
- Average cloud cover in September: 34
The months with the most cloud cover are February and March (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Bristol, ME
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
