A simple, accurate month-by-month guide (calving, river crossings, return south)
The Wildebeest Migration is the world’s largest land-mammal movement — over 1.5 million wildebeest, plus zebra and gazelle, traveling in a continuous cycle across the Serengeti.
While travelers often associate river crossings with Kenya, over 85% of the Migration actually happens in Tanzania, including calving, the main build-up phases, and both sets of river crossings.
Below is the most reliable, up-to-date breakdown of what happens when.
January – March: Calving Season (Ndutu & Southern Serengeti)
Where the herds are
- Ndutu plains (Ngorongoro Conservation Area)
- Southern Serengeti grasslands
What’s happening
By mid-January the herds settle in the south where volcanic soils create highly nutritious grass.
From early February, the migration enters calving season — about 400,000–500,000 calves born in 2–3 weeks.
What makes this season special
- Easiest period to locate the herds (they stay concentrated)
- Intense predator action — lions, hyenas, cheetahs focus on newborn calves
- Incredible photography due to open, short-grass plains
- Calm weather with occasional rains, but very accessible
Peak time
Late January to mid-March
April – May: The Long Rains & Northward Movement
Where the herds are
- Southern Serengeti → Moru Kopjes → Central Serengeti
What’s happening
This is when the northward movement begins. Long columns of wildebeest stretch over kilometers as they follow fresh grass.
Why many travelers overlook this period
- It’s rainy season, so fewer visitors
- Some camps close, but many remain operational
- Grass is lush and green, offering dramatic landscapes
What to expect
- Active migration
- Scattered herds but large groups forming in central regions
- Lower lodge rates and fewer vehicles
Peak time
Late April to late May
June: Western Corridor & Grumeti River
Where the herds are
- Western Serengeti (Grumeti Reserve & surrounding plains)
- Central Serengeti (some herds linger here longer depending on rainfall)
What’s happening
The herds mass around the Grumeti River. These are the first river obstacles of the year, but crossings depend on water levels and are less predictable than the Mara.
Latest insight (based on 2023–2025 patterns)
- Grumeti gatherings are more consistent now than in previous decades
- Crossings happen in small bursts, not the large-scale Mara-style jumps
Why June is excellent
- Dry season begins → roads and game viewing improve
- High predator presence
- Good chance of seeing smaller-scale river crossings
Peak time
Early June to late June
July – September: Mara River Crossings (Northern Serengeti)
Where the herds are
- Northern Serengeti (Kogatende and Lamai regions)
- Some groups move into Maasai Mara, but the majority of herds remain on the Tanzania side longer than in past years
What’s happening
The wildebeest reach the Mara River, the most dramatic stage of the migration: steep banks, fast currents, and crocodiles waiting below.
Most important update (recent years)
- Crossings often begin earlier — sometimes late June
- Herds stay in Kogatende longer due to improved grass and water availability
- Tanzania has more viewing points and fewer crowds than the Kenya side
What to expect
- Multiple crossing points (not one big river)
- Crossings can happen daily or skip days — completely unpredictable
- Excellent predator sightings
Peak time
Mid-July to mid-September
Strong chances also extend into October.
October: Transition Month & Southward Movement Begins
Where the herds are
- Still mostly Northern Serengeti
- Gradually drifting south as dust increases and grazing declines
What’s happening
Although some late-season crossings still happen, most herds begin drifting back into central Serengeti.
Expect
- Mixed herds across central and northern corridors
- Warm, dry conditions
- Good sightings but with movement becoming less concentrated
November: Short Rains & Rapid Southward Return
Where the herds are
- Central Serengeti → Southern Serengeti
What’s happening
As the short rains arrive (usually early November), fresh grass begins to grow in the south. The herds move quickly — sometimes covering huge distances in a matter of days.
Expect
- A major shift back toward the southern plains
- Big herd formations reforming
Peak
Mid-November
Herds reliably push south at this time.
December: Settling Back in the South
Where the herds are
- Southern Serengeti
- Ndutu area (early groups begin gathering)
What’s happening
The cycle resets. The wildebeest settle back into the southern region to prepare for the next calving season.
Expect
- Large herds, good predator action
- Green, beautiful landscapes
- Beginning of calving buildup (January will be stronger)
Quick Summary by Experience Type
Best for Calving & Baby Animals
Late January – March (Ndutu)
Best for Long Herd Columns & Northward Movement
April – early June
Best for Grumeti River Scenes
June (Western Corridor)
Best for Mara River Crossings
Mid-July – mid-September
(continues into early October)
Best for Southward Return
November
Best All-Around Mix of Herds + Weather
December