The best time to visit Tanzania and Kenya for general game viewing is the long dry season from June to October, when animals gather at water and the bush is thin. For the migration river crossings aim for July to September, for calving the short-grass plains around February, and for warm beach days the drier months of the year. Both countries share the same herds and rains, so the right month depends on what you want to see.
The two parks that anchor most combined trips are the Serengeti in Tanzania and the Maasai Mara in Kenya. They sit next to each other across the border, and the same roughly two million wildebeest move between them in a slow annual loop. Where those animals are in any given month is the single biggest factor in choosing your dates, so most of what follows tracks that movement and pins it to the weather in each country.
The short version: July to October is the classic window for the northern Serengeti and Maasai Mara river crossings. January to March is calving season in the southern Serengeti. June to October is the reliable dry season for general game viewing and beaches in both countries. The green months of March to May are wet, quiet, and cheaper.
January to March: Calving in the Southern Serengeti
At the start of the year the herds are gathered on the short-grass plains of the southern Serengeti and the Ndutu area, which straddles the edge of the Ngorongoro Conservation Area. This is calving season, and it is one of the most concentrated wildlife events anywhere in East Africa. Roughly half a million wildebeest calves are born in a tight window, with the peak in February when as many as 8,000 can drop in a single day.
All those newborns pull in every predator on the plains. Lion, cheetah, hyena, and leopard all work the herds, and the open short-grass terrain makes the hunts easier to spot than almost any other time of year. If big-cat action is your priority, February in Ndutu is hard to beat. The land is green from the short rains, the plains are dotted with animals, and this is a Tanzania-side event, so Kenya’s Maasai Mara is quiet for the migration during these months.
This is worth keeping in mind if you are weighing up the two countries. For a fuller look at how the seasons play out south of the border, see our guide to the best time to go to Tanzania. In January and March specifically, the calving is either building up or winding down, so late January into February is the sweet spot rather than the tail ends.
April to May: The Long Rains and the Green Season
April and May bring the long rains to both Tanzania and Kenya. This is the wettest stretch of the year, with afternoon downpours common and some roads turning heavy. Many camps in both countries drop their rates or close entirely, and the Maasai Mara can be very quiet.
The herds spend this period drifting north and west through the central and western Serengeti as the southern plains dry out. Game viewing is still possible, and the scenery is at its greenest, but grass grows tall and animals spread out, which makes sightings less predictable. Skies are dramatic and photography can be lovely when the rain breaks.
The trade-off is real value. If your budget matters more than guaranteed river crossings, and you do not mind wet afternoons, these months offer low crowds and low prices. They are the weakest window for a first-time combined trip focused on the migration, but they suit repeat visitors and photographers who want the parks nearly to themselves.
June: The Herds Move North and the Dry Season Begins
June is a turning point. The long rains ease off, the land starts to dry, and the wildebeest push north through the western Serengeti toward the Grumeti River. The Grumeti crossings can happen this month, though they depend heavily on how much water is in the river, so they are less of a sure thing than the later Mara crossings.
June is a strong month in its own right. Everything is still fairly green after the rains, temperatures are pleasant, and the peak-season crowds have not arrived. You get dry-season access with shoulder-season quiet. The migration is firmly on the Tanzania side in June, so a June trip leans toward the Serengeti rather than the Maasai Mara.
Grumeti versus Mara: The Grumeti River in the western Serengeti sees crossings around June, but they are smaller and water-dependent. The Mara River crossings in the north, from July onward, are the big, dramatic ones most people picture. If crossings are your goal, aim later than June.
July: Crossings Build in the Northern Serengeti
By July the leading edge of the herd reaches the northern Serengeti and the Mara River, the natural border with Kenya. This is when the famous river crossings begin. Wildebeest mass on the banks, hesitate, and then plunge across in the face of strong currents and waiting crocodiles. The momentum grows through the month, with the back half of July often stronger than the start.
Late July is also when the first crossings into the Kenyan side become possible, so this is the beginning of the window where a combined Serengeti and Maasai Mara trip lines up well. The weather is dry and cool, dust is starting to build on the roads, and both parks are entering their busiest stretch. Book camps near the river well ahead, because the good sites fill fast.
August: Peak River Crossings Across the Border
August is the highest-probability month for Mara River crossings on both the Serengeti and Maasai Mara sides. The herds are strung across the border region, moving back and forth, and crossings can happen in either direction on almost any day. If your single goal is to watch a crossing, August gives you the best odds of the year.
This is peak season, and it shows. Both parks are busy, rates are at their highest, and popular crossing points draw a line of vehicles. The weather is reliably dry and mild, which is part of why it is so popular. For the classic combined trip, August is the textbook choice: a few nights in the northern Serengeti followed by a few nights in the Maasai Mara covers both sides of the same river.
Nobody can promise a crossing on a given day. The wildebeest cross when they cross, triggered by rain and grazing that no one can schedule. August simply gives you the most chances.
September to October: Crossings Continue and the Mara Peaks
In September the herds break into smaller groups. Not all of them push into Kenya, so fewer than half remain in the northern Serengeti while the rest spread across the Maasai Mara. This makes the Maasai Mara the stronger bet in September if the migration is your focus, though the Serengeti still holds animals. Smaller groups cross the Mara River back and forth throughout the month, often for no obvious reason.
October continues the crossings and marks the start of the return south. At some point the herds make a final northbound crossing before turning back toward Tanzania, and this southward drift usually gets going in October, sometimes earlier. Late September and October also see the crowds thin from their August peak, so this is a good window if you want crossings with a bit more room. The land is dry and dusty by now, which concentrates resident wildlife around water and keeps general game viewing excellent in both countries.
These months are a fair illustration of how the two destinations differ across the year. If you are still weighing which country to build your trip around, our Kenya vs Tanzania comparison lays out the wider trade-offs beyond just the migration calendar.
November to December: The Short Rains and the Return South
November brings the short rains, lighter and more scattered than the long rains of April and May. They rarely disrupt a trip badly, and they green up the plains again. The herds respond by moving south, drifting back toward the short-grass plains and the Ndutu calving grounds, arriving in the southern Serengeti in late November.
December splits into two moods. Early December can still be showery, but by mid-December the weather steadies and the herds are settling back onto the southern plains, ready to start calving again. Mid-December through February is also a dry, sunny window on the coast, which is why the festive period works well for a safari-and-beach combination. The Maasai Mara is quiet for the migration through these months, so a late-year trip again leans toward Tanzania.
Dry Season Versus Wet Season in Each Country
Beyond the migration, the basic rhythm of both countries is the same. The main dry season runs June to October, with sparse rainfall, thinning vegetation, and animals gathering at water. This is the easiest time for general game viewing in the Serengeti, the Maasai Mara, and the other parks in both countries. Daytime temperatures are mild, often around the low to mid twenties Celsius, with cool mornings.
The wet seasons come in two parts: the long rains of April and May, and the short rains of November into early December. The long rains are the heavier of the two and the quietest time for tourism. The short rains are lighter and rarely spoil a trip. Wet-season travel means greener scenery, newborn animals, dramatic skies, and lower prices, in exchange for taller grass and more spread-out wildlife. Both countries share this pattern closely, which is part of what makes them easy to combine.
Best Beach Timing to Add On
Many combined trips finish on the coast, and the beach seasons line up neatly with the safari dry season. Zanzibar, off the Tanzanian coast, is at its best from June to October and again from mid-December to February, when the weather is dry, the humidity is lower, and the seas are calmer. Diani Beach on Kenya’s south coast follows a similar rhythm, with January to March and July to October the most reliable stretches.
That overlap is convenient. Mid-June through late October gives you strong safari weather and stable coast weather at the same time, so a trip built around the July to October crossings can end with dependable beach days in either Zanzibar or Diani. The festive window of mid-December to February pairs southern Serengeti calving with good coastal weather, which makes it a quieter alternative to the peak crossing months.
When to Combine Both Countries in One Trip
6-Day Arusha, Tarangire, Serengeti & Ngorongoro Safari
5-Day Lake Manyara, Tarangire, Serengeti & Ngorongoro Safari
9-Day Grand Northern Circuit Safari
The tidiest time to put the Serengeti and the Maasai Mara together is late July through October, when the herds are spread across the shared border and river crossings are possible on both sides. A common shape is a few nights in the northern Serengeti followed by a short hop to the Maasai Mara, covering both banks of the Mara River. August maximises crossing odds; September and October shift the balance toward Kenya and thin the crowds.
If crossings are not your main goal, the countries combine well at almost any time because the migration is only one part of the picture. Both hold excellent resident wildlife year round, so a June or an October trip still delivers strong general game viewing alongside whatever the herds are doing. For a closer look at how the herd movement itself unfolds through the Serengeti before it reaches Kenya, see our overview of the Serengeti migration. The one honest caveat, worth repeating, is that no month guarantees a specific event. Timing improves your odds, but the wildebeest and the rains keep their own schedule.
Frequently Asked Questions
What is the single best month for a combined Tanzania and Kenya safari?
August is the most popular choice because it offers the highest probability of Mara River crossings on both the Serengeti and Maasai Mara sides. It is also the busiest and most expensive month. If you want crossings with fewer crowds, late September and October are strong alternatives.
When are the Mara River crossings most likely?
The main crossings run from July to October, with August the highest-probability month. Crossings happen in both directions and cannot be scheduled, since they depend on rain and grazing. Being in the northern Serengeti or the Maasai Mara during this window gives you the best chance, but no operator can promise a crossing on a set day.
When is calving season and where does it happen?
Calving runs from late January to March in the southern Serengeti and the Ndutu area of Tanzania, peaking in February. Around half a million calves are born in a short window, which draws heavy predator activity. This is a Tanzania-side event, so the Maasai Mara is quiet for the migration during these months.
Is it worth visiting during the green season of April and May?
It can be, if value and quiet matter more than guaranteed crossings. April and May are the long rains, the wettest and cheapest months, with low crowds and green scenery. The trade-off is tall grass, more spread-out wildlife, and unpredictable sightings. It suits photographers and repeat visitors more than first-timers chasing the migration.
How much does a combined Tanzania and Kenya safari cost?
Costs vary widely with season and comfort level. Peak crossing months of July to October carry the highest rates for camps and lodges, while the green season of April and May can be a fraction of that. Mid-range combined trips typically run into several thousand dollars per person before international flights, with luxury camps costing considerably more. Booking well ahead for peak season helps secure both space and better pricing.
Can I add a beach holiday to the same trip?
Yes, and the timing works well. Zanzibar is best from June to October and mid-December to February, while Kenya’s Diani Beach is reliable from January to March and July to October. A safari built around the July to October crossings pairs neatly with strong beach weather on either coast, so a few days by the sea makes an easy finish.
