September weather forecastLewiston, ME
September
Weather in September
September in Lewiston brings the initial signs of fall as summer starts to retreat. A distinct drop in temperature becomes apparent, moving the weather towards cooler days. Despite the reduction in sunlight and temperature, September stands out with the lowest monthly rainfall, recording just 0.67" (17mm). Gradual changes in wind speed and relative humidity begin to exhibit characteristics of incoming autumn weather. As daylight hours begin to shorten, the city prepares to embrace the changing season.Temperature
As August shifts into September, a minor alteration in temperatures is observed, with average highs reducing from a moderately hot 76.8°F (24.9°C) to an agreeable 70°F (21.1°C). Lewiston experiences an average nighttime temperature of 50.2°F (10.1°C) in the month of September.Humidity
In Lewiston, the average relative humidity in September is 79%.Rainfall
September is the month with the least rainfall. Rain falls for 7.4 days and accumulates 0.67" (17mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 30min.On the first day of the month, sunrise is at 6:04 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:38 am and sunset at 6:23 pm EDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
In Lewiston, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lewiston, ME
- Average high temperature in September: 70°F
The warmest month (with the highest average high temperature) is July (77.5°F).
The month with the lowest average high temperature is January (27°F).
- Average low temperature in September: 50.2°F
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).
Average pressure in September
Lewiston, ME
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.05"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Lewiston, ME
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is March (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in September
Lewiston, ME
- Average humidity in September: 79%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is November (76%).
Average rainfall in September
Lewiston, ME
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is October (1.69").
The driest month (with the least rainfall) is September (0.67").
Average rainfall days in September
Lewiston, ME
- Average rainfall days in September: 7.4 days
The month with the highest number of rainy days is July (12.7 days).
The month with the least rainy days is February (4 days).
Average snowfall in September
Lewiston, ME
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Lewiston, ME
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Lewiston, 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: 8h and 54min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Lewiston, ME
- Average sunshine days in September: 20 days
The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (16.2 days).
Average UV index in September
Lewiston, 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, October, November and December (UV index 2).
Average cloud cover in September
Lewiston, ME
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 51).
The months with the least cloud cover are August and September (Cloud cover 36).
Average visibility in September
Lewiston, ME
- Average visibility in September: 5mi
The months with the highest visibility are January, November and December (6mi).
The months with the lowest visibility are February, March, April, May, June, July, August, September and October (5mi).
