Summers in Mount Pleasant are warm and humid…however… Mount Pleasant resides next to the Atlantic Ocean and is in close proximity to the beaches (Isle of Palms and Sullivans Island ) which tend to provide a nice breeze/trade wind. 

Besides Summer, Mount Pleasants weather is like the towns name, pleasant. Please see the chart below which outlines the normal highs, lows & averages throughout the year.

 
January:
Normal Low: 37 degrees
Normal High: 58 degrees
Normal Average: 47 degrees
 
February:
Normal Low: 39 degrees
Normal High: 62 degrees
Normal Average: 51 degrees
 
March:
Normal Low: 46 degrees
Normal High: 69 degrees
Normal Average: 58 degrees
 
April:
Normal Low: 52 degrees
Normal High: 76 degrees
Normal Average: 64 degrees
 
May:
Normal Low: 61 degrees
Normal High: 83 degrees
Normal Average: 72 degrees
 
June:
Normal Low: 68 degrees
Normal High: 88 degrees
Normal Average: 78 degrees
 
July:
Normal Low: 73 degrees
Normal High: 91 degrees
Normal Average: 82 degrees
 
August:
Normal Low: 72 degrees
Normal High: 90 degrees
Normal Average: 81 degrees
 
September:
Normal Low: 68 degrees
Normal High: 85 degrees
Normal Average: 77 degrees
 
October:
Normal Low: 55 degrees
Normal High: 77 degrees
Normal Average: 66 degrees
 
November:
Normal Low: 47 degrees
Normal High: 70 degrees
Normal Average: 58 degrees

December:

Normal Low: 39 degrees
Normal High: 62 degrees
Normal Average: 50 degrees

Source:  www.Accuweather.com