There's a notable distinction in the weather between the first half of December and the second. The month begins fairly wet with a good share of rainy days. However, by the middle of the month the precipitation begins tapering off and you'll find more time to go outside and explore when the weather is nice.
Temperature-wise, it can be mixed, depending on where you are in the country. Nairobi sees daytime highs of roughly 75 to 80°F and lows of about 60°F. Meanwhile, the coast is considerably hotter, averaging 88 to 93°F during the day (although evenings don't drop as much, hovering between 73 and 77°F.) You'll want a jacket in the city for nighttime but if you plan to stay at the beach, you can get away with packing much lighter.
In the mountains, it's both cooler and wetter. Hell's Gate National Park, for example, averages about 50% rainy days throughout December (with greater frequency early in the month) and temperatures in the low 60s. The exception is Mount Kenya National Park where it stays mostly dry during this period.
Crowds and Costs
Overall, December is a good month as far as crowd sizes go. Like the weather, it changes throughout the month—the first half being significantly less crowded while the latter is busier as crowds start arriving for Christmas (and the nice weather that comes with it). If you take a group safari, you're bound to have other people in the car with you but it won't be packed to the brim. Similarly, when you're wandering through the tourist attractions in Nairobi, you'll have crowds but you won't be fighting them at every turn.
The costs are better, too. Airlines often run deals this time of year and hotels sometimes offer better rates. They aren't as low as in April or May during the height of the rainy season but they're certainly better than they are mid-summer. Toward the end of the month, prices start going up as the holiday vacationers arrive.
Where to Go
Head to Nairobi where you'll find mostly sunshine mixed with moderate rain showers that are typically quick and intense, rarely lasting all day. It's a delightful time of year to explore the city without the huge crowds—just don't forget to bring a rain jacket for the intermittent showers. One of the best things about the capital this time of year is that it's full of indoor attractions (think museums, art galleries, restaurants, etc.) so that when it's raining you still have things to do. What's more, when the sun is out, it's not overly hot and sweltering.
It's also a fantastic time of year to take a wildlife safari into any of the many national parks. In Samburu National Reserve, for example, you'll see zebras, giraffes, elephants, cheetahs, and all manner of African animals. Amboseli National Park has stunning views of Mt. Kilimanjaro and December is one of the best times to visit because the lack of dust affords better views of the giant mountain. All three parks will be susceptible to some rainy days; however, this usually occurs in the afternoon so if you book your trip in the morning, you can generally count on nice weather.
December is an excellent time to make a visit to Lake Nakuru, too. The famous pink flamingos that the park is known for are abundant this time of year and typically congregating on the lake. The fact that the grass isn't yet overgrown makes them easier to see as well. Masaai Mara is another great destination. The Great Wildebeest Migration is over by this time (although a small number passes through year-round) but the park will be full of tons of other gorgeous creatures and scenic vistas.
The beaches are wet and rainy in December which makes them less than ideal for a vacation destination, even though the temperatures are warm and pleasant. The silver lining, however, it that it's a good time of year to spot the whale shark off the coast, so if you're interested in that sort of thing (as opposed to snorkeling and sunbathing), it may be worth a visit.
What to Do
Visit the vibrant capital city of Nairobi where you can explore the Nairobi National Museum or soak up artwork at the Banana Hill Art Gallery. If you're into more upscale shopping, the Village Market offers trendy boutiques and cafes. The food scene is also exceptional in the city where you can check out places like Talisman, a chic gastro-lounge with European-African fusion cuisine, or Mama Oliech's, a seafood joint that serves delectable fish from Lake Nakuru.
For wildlife lovers, there's no shortage of dazzling savannah full of zebras, elephants, giraffes, lions, cheetahs, rhinoceroses, and more. Book a safari to explore Massai Mara, Samburu National Reserve, Amboseli National Park, or Lake Nakuru, all of which offer incredible opportunities to spot animals in their natural habitats.
In the mountains, discover stunning volcanic gorges and geothermal geysers at Hell's Gate National Park. It's the only park that doesn't have predatory animals which means you can hike or bike freely without the protection of an overland vehicle. Book a mountain biking tour to explore the unique geology of the park and learn more about its history Or, in Mount Kenya National Park, take advantage of the drier conditions to view the country's namesake mountain, along with snow-capped peaks like Batian, Nelion, and Lenana. For more adventurous travelers, try booking a three-day trip to climb to the 17,057-foot summit.
Events in December
Rusinga Cultural Festival: This popular two-day festival, which celebrates Kenya's people and culture, is held right before Christmas on Rusinga Island. In addition to a giant, colorful parade, the event involves music, art, sporting activities, and food, particularly traditional Suba cuisine.
PAWA Festival: The PAWA festival, is a large art festival and block party that takes place every year in December on Koinange Street in Nairobi. The festival showcases visual arts, painting, drawing, theatrical performances, poetry, spoken word, dance, crafts, and a variety of unique workshops.
Traveling to Kenya in December? Check out this great itinerary
Kenya Wildlife Safari - 10 Days: This fun-fulled 10-day itinerary packs in all of the best national parks in Kenya, along with a tour of the vibrant capital city. You'll begin in Nairobi for some urban sightseeing before heading to Amboseli National Park, Hell's Gate National Park, Mount Longonot, Lake Nakuru, Lake Bogoria, and Maasai Mara where you'll see giraffes, zebras, lions, cheetahs, elephants, and other types of spectacular wildlife.