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 sea temperature 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
Entering September, the average high-temperature is recorded at an agreeable 70.7°F (21.5°C), exhibiting a minimal shift from August's 75.9°F (24.4°C). Nighttime temperature reflects an average dip to an enjoyable 65.1°F (18.4°C) in September, subtly cooler than its daytime highs.Humidity
The average relative humidity in September is 76%.Rainfall
September is the month with the least rainfall. Rain falls for 12.6 days and accumulates 2.17" (55mm) of precipitation.Snowfall
April through October are months without snowfall.Ocean temperature
In Shelter Island Heights, in September, the average water temperature is 68.2°F (20.1°C).Note: For most, swimming in 68.2°F (20.1°C) is not a pleasant activity. Breathing becomes increasingly challenging as water temperature descends from 69.8°F (21°C) to 59°F (15°C).
Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:32 pm EDT.
Sunshine
In Shelter Island Heights, the average sunshine in September is 8.8h.UV index
In Shelter Island Heights, New York, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 5 translates into these guidelines:
Exercise caution. Those with pale skin may experience burns in less than half an hour. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
What is the ocean temperature in September?
How many hours of daylight does Shelter Island Heights have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Shelter Island Heights have in September?
How high is the UV index in September?
Average temperature in September
Shelter Island Heights, NY
- Average high temperature in September: 70.7°F
The warmest month (with the highest average high temperature) is August (75.9°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in September: 65.1°F
The month with the highest average low temperature is August (71.2°F).
The coldest month (with the lowest average low temperature) is January (31.3°F).
Average pressure in September
Shelter Island Heights, NY
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Shelter Island Heights, NY
- Average wind speed in September: 12.4mph
The windiest month (with the highest average wind speed) is January (16mph).
The calmest month (with the lowest average wind speed) is July (10.4mph).
Average humidity in September
Shelter Island Heights, NY
- Average humidity in September: 76%
The months with the highest relative humidity are May and June (81%).
The month with the lowest relative humidity is November (72%).
Average rainfall in September
Shelter Island Heights, NY
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is December (3.82").
The driest month (with the least rainfall) is September (2.17").
Average rainfall days in September
Shelter Island Heights, NY
- Average rainfall days in September: 12.6 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in September
Shelter Island Heights, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.36").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Shelter Island Heights, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Shelter Island Heights, NY
- Average sea temperature in September: 68.2°F
The best month for swimming (with the highest average sea temperature) is August (72.1°F).
The coldest month (with the lowest average sea temperature) is February (38.8°F).
Average daylight in September /
Average sunshine in September
Shelter Island Heights, NY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 5min
The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Shelter Island Heights, NY
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is February (12.8 days).
Average UV index in September
Shelter Island Heights, NY
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).
Average cloud cover in September
Shelter Island Heights, NY
- Average cloud cover in September: 33
The month with the most cloud cover is December (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Shelter Island Heights, NY
- 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).
Shelter Island Heights, New York, USA
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