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
As September begins, there is a minor decrease in the average high-temperature, softly falling from a warm 75.9°F (24.4°C) in August to a pleasant 68.9°F (20.5°C). During the month of September, the nighttime temperature in Grand Isle falls to an average of 50.7°F (10.4°C).Humidity
The average relative humidity in September in Grand Isle is 78%.Rainfall
September is the month with the least rainfall in Grand Isle, Vermont. Rain falls for 12.5 days and accumulates 1.81" (46mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:29 pm. On the last day of September, in Grand Isle, sunrise is at 6:50 am and sunset at 6:35 pm EDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In Grand Isle, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The UV index of 3 during September translates into the following guidance:
Prioritize safety - Suggestions to prevent sun damage are offered. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Grand Isle?
What is the average humidity in September in Grand Isle?
What is the driest month in Grand Isle?
How many days does it rain in September in Grand Isle?
When it does not snow in Grand Isle?
Does it snow in Grand Isle in September?
How many hours of daylight does Grand Isle have in September?
When are sunrise and sunset in September in Grand Isle?
How many hours of sunshine does Grand Isle have in September?
How high is the UV index in September in Grand Isle?
Average temperature in September
Grand Isle, VT
- Average high temperature in September: 68.9°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 (24.3°F).
- Average low temperature in September: 50.7°F
The month with the highest average low temperature is July (59.4°F).
The coldest month (with the lowest average low temperature) is January (12°F).
Average pressure in September
Grand Isle, VT
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Grand Isle, VT
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is April (8mph).
The calmest months (with the lowest average wind speed) are July and August (6.1mph).
Average humidity in September
Grand Isle, VT
- Average humidity in September: 78%
The months with the highest relative humidity are January and February (87%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall in September
Grand Isle, VT
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is June (3.23").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Grand Isle, VT
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is June (18.8 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in September
Grand Isle, VT
- Average snowfall in September: 0"
The month with the highest snowfall is February (9.49").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grand Isle, VT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (19.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grand Isle, VT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).
Average sunshine days in September
Grand Isle, VT
- Average sunshine days in September: 15.3 days
The month with the most sunshine days is September (15.3 days).
The month with the least sunshine days is February (6.5 days).
Average UV index in September
Grand Isle, VT
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Grand Isle, VT
- Average cloud cover in September: 32
The month with the most cloud cover is February (Cloud cover 66).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Grand Isle, VT
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January and February (4mi).
Grand Isle, Vermont, USA
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