Weather
April is one of the wettest, rainiest months in Kenya. It's also one of the hotter times of year, especially earlier in the month and along the coast where temperatures range from 86 to 95°F during the daytime. In Nairobi, it's a bit cooler, with daytime averages of 77 to 82°F and nighttimes dropping to about 55°F.
As the rain continues throughout the month—the "green season"—it begins cooling off and by the end of April you can usually count on reduced temperatures. Mosquitos are ubiquitous, especially in the national parks, making insect repellent a mandatory item.
Crowds and Costs
The great thing about the rain? It keeps the masses of tourists away. In fact, April is one of the few times of year where you can book safaris and count on them being practically empty of other guests. The museums and tourist sites in the capital will be much less crowded and the beach resorts will be virtual ghost towns, except during Easter week when locals vacation there. Another silver lining is that the costs are much more reasonable. Most hotels offer special green-season rates during this time and the airlines also drop their prices.
Where to Go
Nairobi is one of the better places to be in Kenya in April. The temperatures are cooler than they are along the coast and there are lots of indoor activities to keep you busy during the afternoon rain showers. Not only that, restaurants and nightclubs often run special promotions this time of year to try to attract tourists during the off-season—so you'll be able to take advantage of lower prices (not to mention shorter lines).
Safaris are doable, but be prepared for rain and less-than-ideal conditions. Mosquitos are rampant and the roads are difficult to navigate. Elephants are less likely to frequent waterholes since the rain keeps them cool on its own, and other wildlife is less concentrated in specific areas. Additionally, the vegetation is thick which makes cats and other game harder to spot (along with the fact that some of them seek shelter during this time). Overall, you probably won't see as much wildlife this time of year.
That said, prices will be much cheaper. It usually only rains in the afternoons which means that if you head out in the morning, you can enjoy a fairly dry tour. Plus, the rain makes the region lush and especially scenic this time of year. Keep in mind, however, that temperatures in the mornings can be quite frigid, so pack accordingly. Maasai Mara makes a good choice, and you can also try a trip to Hell's Gate National Park. Just beware of flash flooding at the latter and be sure to go with a reputable guide.
Generally speaking, you'll want to avoid the beaches in April. They are wet, hot, and rainy with limited opportunities for beach-going or water-based activities.
What to Do
Nairobi offers a wide variety of activities for an April vacation. In the mornings, before the rains begin, check out the unique black rhino sanctuary in Nairobi National Park, just outside of town. In the afternoons, head to sites like the Nairobi National Museum where you can learn more about Kenya's history and culture while also checking out shopping and dining opportunities, as well as the botanical gardens. The capital has a vibrant food scene, too—taste rich Indian biryani at AA Mithaiwalla or try out delectable Kenyan seafood at Tamarind. If you're into nightlife, the city is also full of cocktail lounges, brewpubs, bars, and nightclubs.
If you decide to try a wildlife safari, Maasai Mara is a good option. The mornings are usually fairly clear and the roads are generally accessible, even during the rainy season. In addition to its famous wildebeests (which will be present but not migrating), you may see elephants, zebras, hippos, giraffes, cheetahs, and a host of other animals.
Mount Kenya National Park is another good choice. The expansive park is home to the famous 17,057-foot Mount Kenya which you can see from various points in the park, or even climb if you're feeling adventurous. The rest of the park offers beautiful scenery and a wide variety of wildlife.
Events in April
Easter: In early to mid-April, Kenya celebrates Easter which is a national holiday countrywide. Many locals head to the coast during this time and the beaches can get crowded (this is an exception to the rest of April when crowds tend to be small). In the city, churches hold special masses and there are often public celebrations as well.
Traveling to Kenya in April? Check out this great itinerary
Ultimate Kenya: Mt. Kenya Trek & Maasai Mara Safari - 12 Days: Offering a spectacular blend of national parks and urban attractions, this 12-day itinerary is ideal for April because it skips the destinations that are too rainy this time of year. You'll begin in Nairobi sightseeing and visiting tourist attractions before heading to Mount Kenya National Park. There, you take the three-day trek to the majestic summit of Mount Kenya. Finally, the last five days will be spent touring Lake Naivasha, Maji Moto Maasai Cultural Camp, and the Maasai Mara.