Northern Kenya proper consists of just over a third of the country. North of Marala, Isiolo and Garissa, it includes Turkana, Samburu, the Matthew Mountains, Meru, Mt Nyiru, the Chalbi Desert, and the Shaba Game Reserve.
Save the forested mountain zones - the Matthews Mountains, Mt Nyiru, Mt Kulal, Mt Marsabit and the Ndoto Mountains - and the localised riverine habitats along the Kerio and Ewaso Ngiro rivers, much of northern Kenya is arid to very arid to desert. Altitudinal ranges in the south and along the north-west are in the early thousands, while around and to the east of Lake Turkana, they drop to below 1000m.
Average daytime temperatures in the northern plains range between 20°C and 26°C - though, in some places and certain times of the year, averages are more likely to be in the early thirties, with exceptional zones - the Chalbi desert and Hedad plains, for example - rising into the late forties. Mountain temperatures average out at between 17°C and 19°C.
The pattern of precipitation is nominally bimodal, with the long rains occurring between March and May, the short rains in October and November. Nominally because local trends and the area’s susceptibility to drought combine to make nonsense out of long term predictions: the short rains, for example, fail entirely around Lake Turkana, and are experienced only in November in other areas, while the 2006 to 2009 drought saw the likes of Samburu experience little or no rainfall, month in month out. The picture changes in the mountains, which, known as sky islands, are microclimates unto themselves, and here the pattern is strictly bimodal, with peaks in April and November. Thus, average rainfall levels range between 100mm and 150mm in the Chalbi desert, rise to between 200mm and 300mm in much of the north-east, to between 300mm and 500mm in the south and along the north-west, while the mountains receive anything between 1000mm and 1200mm.
In terms of the climate affecting the movement of animals, the Samburu area and the northern edge of the Laikipia have been especially badly hit by drought, with the rains in April 2009 failing entirely and the Ewaso Ngiro all but running dry. In a normal year, the best time for viewing animals would be the dry season, in December to March and May to September, but the area’s unpredictable climate continues to throw up anomalies. The last big drought broke in late 2009 and there were floods in Samburu in 2010, but - except for sporadic rains in November 2010 and February 2011 - the river is once again dry. The immediate effect, of course, is that animals congregate around the few remaining water sources, carnivores flourish and the viewing is exceptional. However, as the drought sets in, so animals must move or die.
Clearly, journeying further north is hardy travelling indeed, with just the Matthews Mountains and the riverine habitats along the Kerio River offering anything like a traditional wildlife experience. Here, dry season boundaries - June to early October and December to early March - are very distinct and represent the time best for viewing gazelle, oryx, ostrich, elephant, leopard, lion, forest hog and even wild dog. Elsewhere, the major attraction is scenery and culture, with Lake Turkana, the Chalbi Desert and Mt Nyiru being our three main destinations. Like the Matthews, Mt Nyiru is very pleasant most of the year, but wet in April and November. Rain has little effect on travel in northern Turkana and the Chalbi, though April through to August is relatively cooler.