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
The onset of September results in a small decrease in the average high-temperature, moderately receding from a warm 78.8°F (26°C) in August to an agreeable 72.5°F (22.5°C). Uniondale's September nights experience a subtle temperature dip to an average of 64.8°F (18.2°C).Humidity
In September, the average relative humidity is 74%.Rainfall
September is the month with the least rainfall. Rain falls for 9.5 days and accumulates 0.43" (11mm) of precipitation.Snowfall
April through September are months without snowfall.Daylight
In Uniondale, the average length of the day in September 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 6:50 am and sunset at 6:37 pm EDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 5 in September translates into these instructions:
Exercise prevention - Precautions against solar damage are endorsed. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
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?
What is the driest month?
How much does it rain in September?
When it does not snow?
Does it snow in Uniondale in September?
How many hours of daylight does Uniondale have in September?
What time 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
Uniondale, NY
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (37.6°F).
- Average low temperature in September: 64.8°F
The month with the highest average low temperature is July (71.4°F).
The coldest month (with the lowest average low temperature) is January (29.3°F).
Average pressure in September
Uniondale, 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
Uniondale, NY
- Average wind speed in September: 9.7mph
The windiest month (with the highest average wind speed) is January (12.9mph).
The calmest month (with the lowest average wind speed) is July (8.5mph).
Average humidity in September
Uniondale, 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 (71%).
Average rainfall in September
Uniondale, NY
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is July (0.98").
The driest month (with the least rainfall) is September (0.43").
Average rainfall days in September
Uniondale, NY
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is July (12.4 days).
The month with the least rainy days is January (6.2 days).
Average snowfall in September
Uniondale, NY
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.43").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Uniondale, 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 and September (0 days).
Average daylight in September /
Average sunshine in September
Uniondale, 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 54min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Uniondale, NY
- Average sunshine days in September: 18.1 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is July (15.1 days).
Average UV index in September
Uniondale, 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
Uniondale, NY
- Average cloud cover in September: 32
The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Uniondale, 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).
Uniondale, New York, USA
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