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
A subtle shift in South Valley Stream's weather is observed as August turns into September, with the average high temperature reducing from a moderately hot 79.9°F (26.6°C) to a pleasant 73.2°F (22.9°C). South Valley Stream encounters a negligible difference from daytime peaks throughout the September nights, with a low-temperature average of 64.2°F (17.9°C).Humidity
In September, the average relative humidity is 74%.Rainfall
In September, the rain falls for 12.4 days. Throughout September, 1.38" (35mm) of precipitation is accumulated. In South Valley Stream, New York, during the entire year, the rain falls for 135.3 days and collects up to 18.62" (473mm) of precipitation.Snowfall
In South Valley Stream, snow does not fall in April through September.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:38 pm EDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In South Valley Stream, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 5 during September translates into the following directions:
Act with care - Obligation to protect against skin and eye damage is highlighted. The solar radiation around mid-day is intense; avoid the Sun and stay safe. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How many days 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 is the sunrise / sunset in September?
How many hours of sunshine does South Valley Stream have in September?
What is the UV index intensity in September?
Average temperature in September
South Valley Stream, NY
- Average high temperature in September: 73.2°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in September: 64.2°F
The month with the highest average low temperature is August (71.1°F).
The coldest month (with the lowest average low temperature) is January (28.2°F).
Average pressure in September
South Valley Stream, NY
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
South Valley Stream, NY
- Average wind speed in September: 9.1mph
The windiest month (with the highest average wind speed) is January (12.4mph).
The calmest month (with the lowest average wind speed) is July (8mph).
Average humidity in September
South Valley Stream, NY
- Average humidity in September: 74%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is November (72%).
Average rainfall in September
South Valley Stream, NY
- Average rainfall in September: 1.38"
The wettest months (with the highest rainfall) are July and August (2.32").
The driest month (with the least rainfall) is January (0.91").
Average rainfall days in September
South Valley Stream, NY
- Average rainfall days in September: 12.4 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in September
South Valley Stream, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.02").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
South Valley Stream, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
South Valley Stream, NY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
South Valley Stream, NY
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is January (19.8 days).
The month with the least sunshine days is July (13.6 days).
Average UV index in September
South Valley Stream, 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, November and December (UV index 2).
Average cloud cover in September
South Valley Stream, NY
- Average cloud cover in September: 32
The months with the most cloud cover are February and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
South Valley Stream, 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).
South Valley Stream, New York, USA
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