Tanzania
can be visited during all seasons. The standard tourist seasons are in
July-August, when the weather is cool, and dry season parks like
Tarangire are at their prime; and again in December-January, when it's
hotter, but still quite bearable. But to catch the Serengeti at its
best you want to avoid the height of the dry season when virtually all
the animals go on holiday to Kenya. Be prepared if you're heading into
the big wet, as many roads - particularly on the south coast - can
become too squishy to drive on.
Watch out for peak-season hotel prices around the Christmas-New Year holidays and during the July-August peak season.