You can visit the parks all year round although there are distinct rainy and dry seasons. The dry season begins mid-November and lasts until May. The rainy season begins in earnest in June and lasts until mid-November. Some of the heaviest rain can fall August through September. This coincides with the forest’s fruit season, which gorillas love, so it is a very popular time to visit. Bring rain gear! August through mid-October are months with the greatest number of visitors. Some of this is explained by Europe taking its month long summer holiday but fruit season for the gorillas is also a primary reason.
Brazzaville lies below the equator so its dry and rainy seasons are the polar opposite to the parks. Suffice it to say, you cannot time everything perfectly. As CGT accesses and departs the parks by road, the dry season is its preferred season for tours.
January – March:
• It is easier to see the habituated gorillas in the forest as foliage is sparse. More light penetrates the canopy allowing for better photography.
• Sightings of wild gorillas at MbeliBai in Nouabale-Ndoki fall during the dry period.
• A highly prized wildlife sighting is Bongo antelopes in Dzanga-Ndoki National Park which tend to frequent DzangaBai more often and in greater numbers as the dry season wears on. This must be one of the biggest attractions to traveling at the end of the dry season.
• January, February and March are some of the warmest months of the year.
• Water levels in the Sangha River decrease and attractive sandbanks become visible. Navigation of the waterways, however, can be an issue and travel becomes slower.
• Tsetse flies increase in numbers during the dry season. This is most noticeable on the pirogue ride to Mbeli Camp in Nouabale-Ndoki.
• Road access, Brazzaville – Ouesso and Bayanga – Bangui, is easier during the dry period with less chance of getting stuck.
• Brazzaville lies above the equator so January through March falls within its rainy season.
April – May:
The habituated gorillas can be visited all year round but these two months are definitely off season in the parks. April is the very end of the dry season when man and beast is waiting for rain, while the first heavy rains can begin in May and disrupt travel.
June and July:
The dry season is beginning in Brazzaville while the parks enter the rainy season. Temperatures drop and at Bomassa, Nouabale-Ndoki park headquarters, a chilly mist develops early morning on the Sangha River. You will need a fleece. This is a good time to see wild gorillas at MbeliBai in Nouabale-Ndoki. Access to MbeliBai is easier as the river level has risen. The downside to dry season in Brazzaville, below the equator, is monochrome skies, tough for photography. The downside to rainy season in the parks is that a storm can make for some very dark conditions inside the forest. Storms pass, however, and the skies clear after heavy rain.
August and September:
These are the busiest months in Central Africa for visitors. Fruit which the gorillas love comes into season some of which is easily accessible around MbeliBai so wild gorilla sightings tend to be good there. However, an abundance of fruit in the forest overall does mean that gorillas are more dispersed. You may end up walking further to locate the habituated groups.
The “crowds” are beginning to thin in the parks (where beds are limited to between eight and twelve a night) so this becomes another favorite time for CGT. Some last fruit is available in the forest. You must still expect rain but it should be tapering off.
November and December:
You are entering the dry season once again. You might have the parks to yourself.