Stony Brook (NY) monthly weather averages

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Stony Brook

Stony Brook average temperature chart (Celsius) Stony Brook average temperature chart (Fahrenheit)
Average monthly temperatures in Stony Brook (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 2.9 3.8 8.6 14.5 20 24.8 27.6 26.8 23.3 17.7 11.9 5.8
°F 37.2 38.9 47.5 58.1 68.1 76.6 81.7 80.3 73.9 63.9 53.5 42.5

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.

Stony Brook monthly rainfall chart (mm) Stony Brook monthly rainfall chart (inches)
Average monthly rainfall in Stony Brook (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 92 84 107 104 96 88 88 99 89 90 107 106
inches 3.6 3.3 4.2 4.1 3.8 3.5 3.5 3.9 3.5 3.5 4.2 4.2
Rainy days 10 10 11 10 11 10 9 9 8 7 11 11

Average annual rainfall in Stony Brook: 1119.334mm (440.7 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Stony Brook

Stony Brook average daily sunshine chart
Average daily sunshine Stony Brook
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 6.1 6.9 7.8 8.5 9 9.5 9.4 9.1 8 7.4 5.5 5.1

Day / night temperatures

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

Stony Brook average minimum / maximum temperatures (Celsius) Stony Brook average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Stony Brook (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -4.9 -4.5 -0.5 4.1 9.3 14.6 18 17.8 14.1 8.5 3.7 -1.8
Max °C 3.1 4.1 8.9 14.8 20.3 25.1 27.9 27.1 23.5 18 12.2 6
Min °F 23.2 24 31.2 39.3 48.7 58.2 64.3 64 57.4 47.2 38.6 28.8
Max °F 30.4 31.6 39.6 48.9 58.6 67.6 73.2 72.3 65.8 55.8 46.2 35.8

Sea temperature

The graph below shows the average sea temperature.

Stony Brook average sea temperature chart (Celsius) Stony Brook average sea temperature chart (Fahrenheit)
Average sea temperature around Stony Brook 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.

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

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.

Stony Brook relative humidity averages
Average relative humidity in Stony Brook
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
68% 67% 65% 64% 70% 73% 73% 75% 75% 72% 70% 69%