Central Islip (NY) monthly weather averages

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Central Islip

Central Islip average temperature chart (Celsius) Central Islip average temperature chart (Fahrenheit)
Average monthly temperatures in Central Islip (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 3.2 4.2 8.9 14.6 20 24.9 27.8 27.1 23.5 17.9 12.1 6.1
°F 37.8 39.6 48.1 58.3 68 76.8 82 80.8 74.3 64.3 53.8 42.9

Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

Average rainfall & rainy days

The graph below shows the average rainfall and number of rainy days per month.

Central Islip monthly rainfall chart (mm) Central Islip monthly rainfall chart (inches)
Average monthly rainfall in Central Islip (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 92 85 106 104 100 89 91 100 89 88 106 105
inches 3.6 3.3 4.2 4.1 3.9 3.5 3.6 3.9 3.5 3.5 4.2 4.1
Rainy days 10 10 11 10 11 10 9 9 8 7 10 11

Average annual rainfall in Central Islip: 1122.4mm (441.9 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Central Islip

Central Islip average daily sunshine chart
Average daily sunshine Central Islip
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 6 6.8 7.8 8.5 9 9.5 9.4 9.1 8 7.5 5.6 5.1

Day / night temperatures

The graph below shows the daily range of temperatures for each month.

Central Islip average minimum / maximum temperatures (Celsius) Central Islip average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Central Islip (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -4.8 -4.2 -0.2 4.4 9.6 14.9 18.2 18.1 14.3 8.5 3.7 -1.7
Max °C 3.4 4.4 9.2 14.9 20.3 25.2 28 27.4 23.8 18.2 12.3 6.3
Min °F 23.4 24.4 31.7 39.8 49.2 58.7 64.8 64.5 57.7 47.2 38.7 29
Max °F 30.7 32.2 40.1 49.3 58.8 68 73.6 72.9 66.2 55.9 46.4 36.1

Sea temperature

The graph below shows the average sea temperature.

Central Islip average sea temperature chart (Celsius) Central Islip average sea temperature chart (Fahrenheit)
Average sea temperature around Central Islip in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 6.8 4.9 4.8 6.9 11.2 17 21.8 22.8 20.6 16.8 12.9 9.6
°F 44.2 40.8 40.6 44.4 52.2 62.5 71.3 73 69.1 62.3 55.2 49.2

Wind speed

The graph below shows the average wind speed.

Central Islip average winspeed by month (km/h) Central Islip average winspeed by month (mph)
Average wind speed in Central Islip (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 21 21 21 21 18 17 16 16 17 18 19 20
mph 13 13 13 13 11 11 10 10 11 11 12 13

A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

Relative humidity

The graph below shows the average relative humidity.

Central Islip relative humidity averages
Average relative humidity in Central Islip
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
67% 66% 65% 64% 70% 72% 73% 75% 75% 71% 70% 68%