It is easiest to talk about when not to go to Tanzania. The major rainy season is from early April to late May, and the short rains are in November. These months have the fewest visitors. Rain or snow can be expected every day, but not the entire day. July and August are the busiest months.
The best time to see the migration in Tanzania is often January-March and June-August. In the Kenya, it is often best September-October. You will see an abundance of wildlife all year round.
Kilimanjaro is climbable all year round. The best months to climb are December-March, and September-October, which are the warmest and driest months. The next best are July and August, but they are colder. Rain and snow may be encountered any time of the year!
Temperatures range from 25 to 30 degrees Celsius at the foot of the mountain and -15 to -20 degrees Celsius on top plus wind chill. Lower down, it can be wet and humid, but higher up, there can be snow. The mountain is most picturesque right after the main rainy season with the snow still visible.
It is usually clear in the mornings and in the evenings, but clouds move in late morning sometimes bringing rain or snow in the afternoon. Views of the summit can be seen earlier in the morning and also at sunset. At nighttime, you will see the lights of Moshi and Arusha below you, and, of course, the spectacular Southern Cross constellation in the sky. Mt. Meru can be seen in the distance.
At the equator, the time of sunrise and sunset do not vary significantly from one season to another. Sunrise will be around 6:30am and sunset will be around 6:30pm. This is the land of “early to bed and early to rise”.