Grand Isle (LA) monthly weather averages

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Grand Isle

Grand Isle average temperature chart (Celsius) Grand Isle average temperature chart (Fahrenheit)
Average monthly temperatures in Grand Isle (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 16.3 17.7 21.2 25.1 28.5 31.2 32.1 31.9 30.2 26.2 21.7 18.2
°F 61.4 63.9 70.2 77.1 83.3 88.1 89.7 89.5 86.3 79.1 71.1 64.7

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.

Grand Isle monthly rainfall chart (mm) Grand Isle monthly rainfall chart (inches)
Average monthly rainfall in Grand Isle (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 127 123 113 120 124 136 168 169 165 82 97 114
inches 5 4.8 4.5 4.7 4.9 5.3 6.6 6.7 6.5 3.2 3.8 4.5
Rainy days 10 8 8 6 7 10 14 13 10 5 7 9

Average annual rainfall in Grand Isle: 1478.117mm (581.9 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Grand Isle

Grand Isle average daily sunshine chart
Average daily sunshine Grand Isle
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 6.2 7.1 8.2 9.7 10 9.4 8.8 8.6 8.1 8.3 7 6.4

Day / night temperatures

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

Grand Isle average minimum / maximum temperatures (Celsius) Grand Isle average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Grand Isle (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 6.9 8.4 12 16.1 19.6 22.6 23.5 23.4 21.8 16 12 8.6
Max °C 16.6 17.9 21.5 25.3 28.7 31.4 32.3 32.1 30.4 26.4 22 18.4
Min °F 44.4 47.1 53.6 60.9 67.3 72.6 74.3 74.2 71.2 60.9 53.6 47.5
Max °F 53.1 55.7 62.1 69.2 75.5 80.6 82.2 82 78.9 70.2 62.6 56.3

Sea temperature

The graph below shows the average sea temperature.

Grand Isle average sea temperature chart (Celsius) Grand Isle average sea temperature chart (Fahrenheit)
Average sea temperature around Grand Isle in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 18.4 18 19.1 21.6 25 28.2 29.6 29.7 28.6 25.5 22.4 20.1
°F 65.1 64.3 66.4 70.8 77 82.8 85.2 85.5 83.4 78 72.3 68.2

Wind speed

The graph below shows the average wind speed.

Grand Isle average winspeed by month (km/h) Grand Isle average winspeed by month (mph)
Average wind speed in Grand Isle (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 16 16 17 16 14 12 10 10 12 12 14 15
mph 10 10 10 10 9 7 6 6 7 8 9 9

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.

Grand Isle relative humidity averages
Average relative humidity in Grand Isle
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
76% 73% 73% 73% 74% 76% 79% 79% 78% 75% 77% 77%