September weather forecast
Upper Brookville, NY

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Weather in September

The first month of the autumn, September, is still a warm month in Upper Brookville, New York, with temperature in the range of an average high of 73.4°F (23°C) and an average low of 63.5°F (17.5°C).

Temperature

As Upper Brookville enters September, the average high-temperature subtly lowers from the 80.4°F (26.9°C) of August to a still warm 73.4°F (23°C). An average nighttime temperature of 63.5°F (17.5°C) is noted during the month of September.

Humidity

In September, the average relative humidity is 73%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.9 days and accumulates 2.4" (61mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:21 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.

Sunshine

In September, the average sunshine is 9h.

UV index

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, a daily UV index of 5 turns into the following recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Upper Brookville, is 73.4°F (23°C), while the low-temperature averages to 63.5°F (17.5°C). In July, the average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, is calculated to be 86°F (30°C).

What is the average humidity in September?

In September, the average relative humidity is 73%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 12.9 days and typically collects 2.4" (61mm) of precipitation.

How much does it rain in September?

In Upper Brookville, in September, during 12.9 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

When it does not snow?

In Upper Brookville, New York, snow does not fall in May through October.

What is the average length of the day in September?

In Upper Brookville, the average day length in September is 12h and 27min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:21 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 9h.

What is the UV index reading in September in Upper Brookville?

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Upper Brookville, NY

Average temperature in September - Upper Brookville, NY
  • Average high temperature in September: 73.4°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (36.5°F).

  • Average low temperature in September: 63.5°F

The months with the highest average low temperature are July and August (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.3°F).

Average pressure in September
Upper Brookville, NY

Average pressure in September - Upper Brookville, 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
Upper Brookville, NY

Average wind speed in September - Upper Brookville, NY
  • Average wind speed in September: 8.3mph

The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).

Average humidity in September
Upper Brookville, NY

Average humidity in September - Upper Brookville, NY
  • Average humidity in September: 73%

The months with the highest relative humidity are February, May and December (75%).
The months with the lowest relative humidity are August and November (71%).

Average rainfall in September
Upper Brookville, NY

Average rainfall in September - Upper Brookville, NY
  • Average rainfall in September: 2.4"

The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.4").

Average rainfall days in September
Upper Brookville, NY

Average rainfall days in September - Upper Brookville, NY
  • Average rainfall days in September: 12.9 days

The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (9.3 days).

Average snowfall in September
Upper Brookville, NY

Average snowfall in September - Upper Brookville, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Upper Brookville, NY

Average snowfall days in September - Upper Brookville, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Upper Brookville, NY

Average daylight in September / Average sunshine in September - Upper Brookville, 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: 9h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in September
Upper Brookville, NY

Average sunshine days in September - Upper Brookville, NY
  • Average sunshine days in September: 15.2 days

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is July (10.6 days).

Average UV index in September
Upper Brookville, NY

Average UV index in September - Upper Brookville, 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
Upper Brookville, NY

Average cloud cover in September - Upper Brookville, NY
  • Average cloud cover in September: 33

The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 29).

Average visibility in September
Upper Brookville, NY

Average visibility in September - Upper Brookville, 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).

Upper Brookville, New York, USA

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