Then the seasons switch, and the northern half gets summer while the southern part cools into winter.
(the seasons; switch; T:Then) (the northern half; gets; summer; T:while the southern part cools into winter) (the southern part; cools; T:into winter)
the seasons the northern half the southern part
switch gets cools
T:Then
summer T:while the southern part cools into winter
T:into winter