Islip
New York, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Islip, NY

The first month of the autumn, September, is also a moderately hot month in Islip, New York, with temperature in the range of an average low of 57.6°F (14.2°C) and an average high of 73.8°F (23.2°C).

Temperature

In Islip, the average high-temperature marginally drops, from a moderately hot 80.4°F (26.9°C) in August, to a still warm 73.8°F (23.2°C). In September, in Islip, New York, the average low-temperature is 57.6°F (14.2°C).

Rainfall

In Islip, during 8.6 rainfall days, 3.6" (90.9mm) of precipitation is typically accumulated. In Islip, during the entire year, the rain falls for 118.9 days and collects up to 46.2" (1174.5mm) of precipitation.

Snowfall

Throughout the year, in Islip, 24.8" (629.9mm) of snow is accumulated.

Ocean temperature

In September, the average ocean temperature is 69.6°F (20.9°C). For swimming, a surface water temperature of 69.6°F (20.9°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

Daylight

In September, the average length of the day is 12.4h.

What is the temperature in September in Islip?

The average high-temperature, in September, in Islip, New York, is 73.8°F (23.2°C), while the average low-temperature is 57.6°F (14.2°C).

How much does it rain in Islip in September?

In Islip, in September, it is raining for 8.6 days, with typically 3.6" (90.9mm) of accumulated precipitation.

How cold is the water in September in Islip?

In Islip, in September, the average water temperature is 69.6°F (20.9°C). For most, swimming in 69.6°F (20.9°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

What is the average length of the day in September in Islip?

The average length of the day in September in Islip is 12.4h.
Average temperature in September - Islip, NY
  • Average high temperature in September: 73.8°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (38°F).

  • Average low temperature in September: 57.5°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (23.3°F).

Average rainfall in September - Islip, NY
  • Average rainfall in September: 3.6"

The wettest month (with the highest rainfall) is March (4.4").
The driest month (with the lowest rainfall) is February (3.3").

Average rainfall days in September - Islip, NY
  • Average rainfall days in September: 8.6 days

The month with the highest number of rainy days is April (11.3 days).
Months with the lowest number of rainy days are August and October (8.5 days).

Average snowfall in September - Islip, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is February (7.1").
Months with the lowest snowfall are May, June, July, August, September and October (0").

Average snowfall days in September - Islip, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (3.7 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in September - Islip, NY
  • Average sea temperature in September: 69.6°F

The best month for swimming (with the highest average sea temperature) is August (74°F).
The coldest month (with the lowest average sea temperature) is February (39.7°F).

Average daylight in September - Islip, NY
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 15.1h).
The month with shortest days is December (Average daylight: 9.3h).