Louisiana Coast is warm and humid with annual rainfall amounts between 40 and 70 inches.  Rainfall generally comes in the form of large storms, so annual rates are dependent on weather anomalies such as El Nino.  Extratropical storms in the winter and thunderstorms and tropical storms in the summer and fall supply most of the precipitation.  Tropical storms hit Louisiana coastal wetlands approximately every 4 years.  Hurricanes have a much less predictable pattern.  Monthly precipitation varies from July being the wettest and October the driest.
The Louisiana Coast is at approximately 30 degrees North latitude, and during the summer the peak solar insolation of 600 calories/square centimeter represents the highest solar insolation on the planet.  Because of this, the growth potential during the summer is the best in the world.  Mean temperatures tend to follow insolation closely, resulting in winter temperatures averaging 14 degrees Celcius and summer temperatures reaching 30 degrees Celcius.  The massive volume of water present in the wetlands creates a moderating effect, keeping the summers very hot and humid.  Frost is infrequent with an average of less than 50 days with frost risk annually.  Water temperatures in the wetlands are closely related to air temperatures due to the low volume to surface area ratio.  

Mean precipitation in Louisiana mean precipitation

Mean temperature in Louisiana
mean temperature

Impacts of Hurricane Andrew on coastal wetlands
Hurricane Andrew was a relatively small hurricane but when it came ashore on August 26th, 1992, it hit the Louisiana Coastal wetlands hard.  Wind gusts of 169 mph and over 7 inches of rain resulted in a storm surge of 9ft.  Despite the huge storm surge, little coastal flooding occurred.  Nearly 80% of the trees in some coastal forests were knocked down.  The heavy wave action caused resuspension of toxic anaerobic soils, which killed 182 million freshwater fish in the Atchafalaya River basin alone.  The floating marsh mats were the most damaged through physical movement due to wind and wave action.  Other sections of the marsh were damaged through scour. 


Wetland Formation
Animal Life
Plant Life
Ecosystem Function
Human Settlement
Human Interactions