The herds have reached the grassy Northern plains, where they stay 2-3 months to graze, moving from a pasture to another, following the sporadic rainfalls in search of new pastures. 
You can spot the herds several times as they move from the asai Mara and the Serengeti Mara.
It’s the time of rest for the Great Migration, when wildebeests and zebras are just busy to graze, the cubs born in January grow and the females bring forth their pregnancies, and all the animals accumulate energy in view of making their return journey to the Southern plains of the Serengeti and the Ngorongoro Conservation Area.
Some herds are still at the Serengeti Mara, others cross the river Mara several times and others again do not cross it and decide to remain in this area of the Serengeti, that is relatively grassy with good pastures and abundance of water.
The crossing is a very critical stage of the journey and many animals are frightened. The river Mara is infested with Nile crocodiles, in many places the sandy banks are very steep and the waters are often raging because of the size of the river, sporadic rainfalls that swell it rapidly and the slope of its bed.
Wildebeests carefully assess at what point to cross; they monitor the flow of the river, the presence of rapids and large boulders in the water and other elements that make the crossing a hazard, last but not least, they try to spot the crocodiles lurking in the water, just awaiting for their crossing.
They prefer more gentle slopes, but it often happens to see them jumping down from steep sandy banks. They as well monitor the opposite bank and, also in this case, they choose a point along the bank where the slope is easier and there are no trees or shrubs, where lurking predators can hide. 

Where is possible to spot the herds of Great Migration in August, September and October

Lobo: some herds stay in the very scenic area before they head further North. It may happen that some herds return here in these months in search of new pastures.
Serengeti Mara and the Lamai Triangle: this far-reaching Northernmost part of the Serengeti is located right at the border with Kenya and the Maasai Mara Reserve.
The landscape here is mainly flat with pastures, bushes and some trees. It is dominated by the river Mara with its numerous bends, where you can patiently spot the crossing.
Apart from the Great Migration herds, the area is inhabited by lions, leopards, cheetahs, different species of antelopes and gazelles, and hyenas.
There are also elephants here, though in few numbers.
Maasai Mara: this area is the natural continuation of the Serengeti Mara.
It features extensive plains and gently-rolling hills with grassy pastures with shrubs and trees.
A high number of animals can be spotted here, namely predators, such as lions, leopards, cheetahs and hyenas waiting the herds.
There is no lack of herbivorous either, such as elephants, giraffes, buffalos and different species of antelopes and gazelles.
Numerous flocks of noisy hippos and fierce Nile crocodiles patiently wait for the herds to cross the river or the animals to go to the river to drink water, looking for the right moment to attack.