Search Document Types   →   Building Science Digests   →   Side Bar: Hygrothermal Regions

Side Bar: Hygrothermal Regions



Subarctic and Arctic

A subarctic and arctic climate is defined as a region with approximately 12,600 heating degree days (65 degrees F basis) [7,000 heating degree days (18 degrees C basis)] or greater.


Very Cold

A very cold climate is defined as a region with approximately 9,000 heating degree days or greater (65 degrees F basis) [5,000 heating degree days (18 degrees C basis)] or greater and less than 12,600 heating degree days (65 degrees F basis) [7,000 heating degree days (18 degrees C basis)].


Cold    

A cold climate is defined as a region with approximately 5,400 heating degree days (65 degrees F basis) [3,000 heating degree days (18 degrees C basis)] or greater and less than approximately 9,000 heating degree days (65 degrees F basis) [5,000 heating degree days (18 degrees C basis)]


Mixed-Humid  

A mixed-humid and warm-humid climate is defined as a region that receives more than 20 inches (50 cm) of annual precipitation with approximately 4,500 cooling degree days (50 degrees F basis) [2,500 cooling degree days (10 degrees C basis)] or greater and less than approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days (10 degrees C basis)] and less than approximately 5,400 heating degree days (65 degrees F basis) [3,000 heating degree days (18 degrees C basis)] and where the average monthly outdoor temperature drops below 45 degrees F (7 degrees C) during the winter months.


Marine

A marine climate meets is defined as a region where all of the following occur:

  • a mean temperature of the coldest month between 27 degrees F (-3 degrees C) and 65 degrees F (18 degrees C);
  • a mean temperature of the warmest month below 72 degrees F (18 degrees C);
  • at least four months with mean temperatures over 50 degrees F (10 degrees C); and
  • a dry season in the summer, the month with the heaviest precipitation in the cold season has at least three times as much precipitation as the month with the least precipitation


Hot-Humid       

A hot-humid climate is defined as a region that receives more than 20 inches (50 cm) of annual precipitation with approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days (10 degrees C basis)] or greater and where the monthly average outdoor temperature remains above 45 degrees F (7 degrees C) throughout the year.

This definition characterizes a region that is similar to the ASHRAE definition of hot-humid climates where one or both of the following occur:

  • a 67 degree F (19.5 degrees C) or higher wet bulb temperature for 3,000 or more hours during the warmest six consecutive months of the year;  or
  • a 73 degree F (23 degrees C) or higher wet bulb temperature for 1,500 or more hours during the warmest six consecutive months of the year.


Hot-Dry, Warm-Dry and Mixed-Dry

A hot-dry climate is defined as region that receives less than 20 inches (50 cm) of annual precipitation with approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days (10 degrees C basis)] or greater and where the monthly average outdoor temperature remains above 45 degrees F (7 degrees C) throughout the year.

A warm-dry and mixed-dry climate is defined as a region that receives less than 20 inches (50 cm) of annual precipitation with approximately 4,500 cooling degree days (50 degrees F basis) [2,500 cooling degree day (10 degrees C basis)] or greater and less than approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days (10 degrees C basis)] and less than approximately 5,400 heating degree days (65 degrees F basis) [3,000 heating degree days (18 degrees C basis)] and where the average monthly outdoor temperature drops below 45 degrees F (7 degrees C) during the winter months.

There are currently no items in this folder.