September weather forecastGreenwich, NY
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Greenwich, New York, with an average temperature varying between 71.6°F (22°C) and 51.1°F (10.6°C).Temperature
In Greenwich, the average high-temperature in September slightly decreases from a moderately hot 78.6°F (25.9°C) in August to a pleasant 71.6°F (22°C). Greenwich experiences a mean temperature of 51.1°F (10.6°C) during September nights.Humidity
In September, the average relative humidity is 78%.Rainfall
In September, the rain falls for 10.1 days. Throughout September, 1.38" (35mm) of precipitation is accumulated. In Greenwich, during the entire year, the rain falls for 123.3 days and collects up to 18.62" (473mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:19 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:36 pm EDT.
Sunshine
In September, the average sunshine is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: In September, an average UV index of 4 transforms into the following instructions:
Exercise caution. Those with pale skin may experience burns in less than half an hour. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Greenwich, NY
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (27.9°F).
- Average low temperature in September: 51.1°F
The month with the highest average low temperature is July (58.6°F).
The coldest month (with the lowest average low temperature) is January (16.3°F).
Average pressure in September
Greenwich, NY
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Greenwich, NY
- Average wind speed in September: 5.5mph
The windiest months (with the highest average wind speed) are January and April (7.5mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Greenwich, NY
- Average humidity in September: 78%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Greenwich, NY
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is July (2.01").
The driest month (with the least rainfall) is March (1.1").
Average rainfall days in September
Greenwich, NY
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is June (14.1 days).
The month with the least rainy days is January (4 days).
Average snowfall in September
Greenwich, NY
- Average snowfall in September: 0"
The month with the highest snowfall is February (5").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Greenwich, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (9.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Greenwich, NY
- Average daylight in September: 12h and 30min
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 6min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 3h and 48min).
Average sunshine days in September
Greenwich, NY
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is January (20.4 days).
The month with the least sunshine days is June (14.3 days).
Average UV index in September
Greenwich, NY
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Greenwich, NY
- Average cloud cover in September: 34
The month with the most cloud cover is February (Cloud cover 59).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Greenwich, NY
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, May, October, November and December (6mi).
The months with the lowest visibility are February, June, July, August and September (5mi).





