Big herds of wildebeest gather in the southern plains of the Serengeti and Ndutu regions. Peak calving season occurs over about 2 to 3 weeks during February. Many predators are attracted to the area. Visibility is usually excellent with animals on the open plains. Book well in advance for this time of year if you want to visit Ndutu and the southern plains. January and February are reasonably dry, but March sees the start of the rainy season.

This is the low season, but is still a good time to travel There are fewer visitors, less crowding, less dust. It is the rainy season (the long rains) but it does not rain all day, every day. In southern Tanzania, many camps close during this time as some roads become impassable. Skies with thunderclouds are often dramatic and sunsets are spectacular which make breathtaking backdrops for photographs. Most lodges and hotels offer lower rates at this time. In general, the herds gather around central Serengeti and start to move towards Grumeti.

Peak season for Tanzania. The herds of wildebeest move northwards toward Kenya. The Seronera region, Grumeti region and northern regions are the place to be.
The herds cross the Grumeti river and start to move toward the Mara river in the northern Serengeti. The exact timing of their movements depend on annual rainfall patters and differ from year to year.

It is still peak safari season for both northern and southern Tanzania. By now, the Great Migration has reached the Maasai Mara in Kenya. Thousands of wildebeest make the dangerous river crossings - one of the most spectacular annual wildlife scenes you can witness. Huge crocodiles patrol the rivers waiting for the herds to cross. Many die during the crossings, but thousands more make it across safely. Hundreds of thousands of wildebeest roam the Maasa Mara reserve while huge herds still remain in the northern reaches of the Serengeti. Time and patience usually pay off for those who stay in the area at this time - further river crossings often occur but the exact time and place is impossible to predict. Sometimes the herds bunch together on the riverbank for days before they start to cross. You need a bit of luck to witness a river crossing. Kenya may be a better destination during this time if you want to see the migration and the river crossings.
By October, the herds start moving back south again, into the Serengeti.

The larger herds start to make their way back from the north. The migration continues southwards across the Serengeti toward the southern plains. The short rains bring the first green grass to the southern plains. Once more, the migration cycle begins anew.
This is a less crowded time to visit Tanzania but a really good option for those who still want great game viewing with fewer vehicles around.
Short, dramatic thunderstorms are possible.