Blog 3

Climate Controls

Source: http://www.epodunk.com/cgi-bin/genInfo.php?locIndex=13090

At the macro scale, Charleston’s climate is controlled by its location in the Northern Hemisphere on the North American continent.  At the meso scale, Charleston’s climate is controlled by its location on the Atlantic Coast and the Bermuda High Air Mass. In addition, Charleston is located at the meeting of several rivers.  

Source: http://mappery.com/map-of/Charleston-South-Carolina-Tourist-Map-2

Historical Trends

Source: NOAA

Source: NOAA

For both the average maximum and minimum temperatures there was a slight decrease in the month of January.  For the maximum there was a slight increase until the 1950's before it began to decrease.

Source: NOAA

Source: NOAA

An increase can be seen in both the average maximum and minimum temperatures in the month of July.  The increase in the minimum is much more significant.  Also, while the average maximum temperature has risen since 1893, it reached a peak in the 1970's and has begun to decrease.

An explanation for the increase in the minimum temperature in July is the creation of an urban heat island.  As the city expanded and more asphalt became present the radiation from the sunny days in July is absorbed.  This energy is then released at night in the form of heat, keeping the temperature at night higher than in the past.

Koppen-Geiger climate classification system

Source: http://people.eng.unimelb.edu.au/mpeel/koppen.html

Charleston, SC falls under the Cfa classification.  In order for a location to fall under this classification the coldest month must fall under 64.4 F and the warmest month is over 71.6 F.  There should be also be 4 months that are above 50 F.  The graph below confirms this.

Source:  www.weather.com