The best time to visit Botswana is between April and November for the Okavango Delta and Northern Botswana, but summer is the best time for the central Kalahari whilst Tuli & Makgadikgadi are year round destinations.
The months between April and November, when large number of animals migrate towards the waterways of the Okavango Delta, is the best time to visit the Delta - specifically the months of July, August and September.
These are the cool winter months where almost all of the regions game has migrated towards the more permanent water sources, making for intense game viewing. The vast majority of safaris focus most of their time in the private concessions of the Okavango Delta and the Linyanti Reserve where the flood waters should have arrived in all areas from the Okavango River.
The rainy season, from January to March is a less common time to visit, but it sees the migration of large numbers of game into the summer grazing areas of the Central Kalahari Game Reserve, while the Okavango Delta comes alive with sounds of hundreds of bird species.
This period usually experiences the majority of the country's annual rainfall, although very low (see weather) as Botswana is a semi-arid land. This is often a pleasant time of year to travel.
In March and April thousands of zebras and other animals migrate towards the Savuti area of Chobe National Park.
November and December - the calving months - are an excellent time to witness nature's own timetable of regeneration. Keep in mind that summers (particularly from December through to February) can become hot, and rain may make roads muddy.
During the summer season, Botswana becomes a productive paradise interspersed with vibrant floral displays and a kaleidoscope of colours. Theres an explosion of new life: many species give birth to their young and areas like the Central Kalahari and Kgalagadi are at their wildlife viewing peak.
Predator sightings are frequent as they take full advantage of the abundance of inexperienced younger prey. It is also the best season for birding. Several bird species display their splendid breeding plumage and many migratory species are present.
Makgadikgadi Pans National Park is worth visiting year round for its spectacular salt pans, Bushmen and meercats. Desert areas such as Central Kalahari and Nxai Pan tend to be at their best in the green season November to May, when the migratory herds pass through.
Tuli Game Reserve (in the south east) is a good quality year round game area, mostly accessed from and combined with South Africa.