high season is mid-June to October, and low season is November, January to April.
Season Three aired from April 2013 to January 2014.
The month of January in the USofA is in the middle of winter.
Winter
US: January 3rd, 2013 - April 11th, 2013UK: April 15th, 2013 - June 7th, 2013Australia: May 13th 2013 - July 5th, 2013
November to January
Episode 1 of season 4 aired in the US on January 31, 2008Episode 1 of season 5 aired in the US on January 21, 2009
March, April and May
3.The series ran from April 23rd, 2010 to January 3rd, 2013
The premiere was January 31st 1999howevertechnically the official first season began on April 11th, 1999
Season One started January 11th 2011. Season Two started April 28th 2012.
April through June is generally considered tornado season.