Zone A – more than nine consecutive wet months, and two or less consecutive dry months.
Zone B – seven to nine consecutive wet months and three or less consecutive dry months.
Zone C – five to six consecutive wet months and three or less consecutive dry months.
Zone D – three to four consecutive wet months and two to six consecutive dry months.
Zone E – up to three consecutive wet months and up to six consecutive dry months.

* Wet and dry are defined as more than 200 mm rainfall/month and less than 100 mm/month