Like in the rest of Tanzania, the climate pattern here is characterised by the dry season and the wet season.
The wet or green season lasts from November to May, that includes the small rain season limited to November, the wettest month of the year, and December; while the heavy rains occur from March, with the monsoon rains, until mid-May, at this time of the year, the peak of rainfalls occurs in April, while there are no rainfalls in January and in the first half of February.
This is an exciting time of the year, when trees and prairies are green and lush, populated by many wild animals, especially in the Northern plains where the Great Migration of wildebeests and zebras can be spotted from December to March; this is also the period coinciding with the birth of the puppies, that takes place mainly in February; an event attracting many predators.
The dry season is from June to October and is usually the best time to spot the animals who gather near the available water sources; there is lack of vegetation that makes sightings much easier.
From June to mid-August the Ngorongoro Crater is veiled with fog, that is very thick in the morning and only dissipates in the late afternoon, when the air has become warmer; after mid-August this phenomenon is reduced until it disappears in September and October.
Game drives in the Ngorongoro Crater are fantastic in this time of the year, that is also the best time to visit the Empakaai Crater and the Ndutu Lake, where the resident wild animals gather around permanent water sources.
The climate of the highlands tends to be more unstable throughout the year and considerably variable compared to areas at a lower altitude, this is mainly due to day-night thermal excursion.