Month by month
Tsavo in April
April is the month Tsavo's own sales pitch gives up on, which is exactly what makes it interesting. The parks are as empty of people as they ever get, the beds cost roughly half their August price, and the storms build the best skies of the year.
If you only want the answer
April is the low point for game viewing and the low point for prices, and the second fact is the only good reason to pick it. Come for birds, storm light and empty roads, not for cats.
The honest numbers
The Voi normals log April at 50 mm over 8 rain days with highs of 31.3°C, which on paper is less rain than March records. The wettest-month reputation still holds up on the ground, because the soil is already saturated when April starts, the individual storms run heavier, and the month sits square in the middle of the long rains rather than at their leading edge.
The result is Tsavo at maximum thickness: bush closed in, every pan holding water, and the herds spread across country you cannot see into.
What half price actually buys
Satao Camp drops from $243 to $135 full board in April and Voi Wildlife Lodge from $128 to $95, and similar cuts run across the mid-range. Park fees do not move, so the flat $80 per park per day becomes a bigger share of a cheap trip; budget for that rather than resenting it.
Expect elephants washed back to grey, since the rain rinses off the red dust that makes the postcard shots, and expect to work hard for every sighting. The compensation is having Lugard's Falls or the Shetani lava flow entirely to yourself under a five-mile thunderhead.
If you come anyway
Tsavo never closes, so the question is only how you manage the mud. Base yourself in the Voi Gate cluster with the tarmac A109 at your back, run short morning loops before the afternoon build-up, and accept that some tracks will simply be off the menu.
A proper 4x4 is non-negotiable this month, and the no-off-road rule still applies even when the main track is a trench. Birders should ignore all of the above and book without hesitation, because the park in full leaf and full song is their version of peak season.