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 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's arrival aligns with a minor decrease in average high-temperatures, from August's moderately hot 77.4°F (25.2°C) to a pleasant 69.6°F (20.9°C). Rochester sees an average low-temperature of 52.9°F (11.6°C) during September.Humidity
In September, the average relative humidity is 79%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.8 days and typically collects 1.5" (38mm) of precipitation.Snowfall
In Rochester, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:08 am and sunset at 7:18 pm. On the last day of September, sunrise is at 6:40 am and sunset at 6:26 pm EDT.
Sunshine
In Rochester, the average sunshine in September is 8.3h.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 exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 4 suggests these recommendations:
Adopt protective measures - It is advised to guard against sun damage. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Rochester, NH
- Average high temperature in September: 69.6°F
The warmest month (with the highest average high temperature) is July (78.3°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 52.9°F
The month with the highest average low temperature is July (60.3°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Rochester, NH
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Rochester, NH
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in September
Rochester, NH
- Average humidity in September: 79%
The months with the highest relative humidity are January and February (82%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Rochester, NH
- Average rainfall in September: 1.5"
The wettest months (with the highest rainfall) are October and December (3.11").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in September
Rochester, NH
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (15.1 days).
The month with the least rainy days is February (6.8 days).
Average snowfall in September
Rochester, NH
- Average snowfall in September: 0"
The month with the highest snowfall is December (6.69").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rochester, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rochester, NH
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Rochester, NH
- Average sunshine days in September: 16.2 days
The month with the most sunshine days is November (16.9 days).
The month with the least sunshine days is April (13.3 days).
Average UV index in September
Rochester, NH
- Average UV index in September: 4
The months with the highest UV index are July and August (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
Rochester, NH
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Rochester, NH
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, October, November and December (6mi).
The months with the lowest visibility are May, June, July, August and September (5mi).
Rochester, New Hampshire, USA
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