Physical and Topographic features
The county is characterized by undulating topography. The overall slope of the land is towards the West, consequently drainage is in that direction. The county forms a hilly shelf between the Mau Escarpment and the lowlands of Kisumu County. To the North West are the hilly areas of Kipkelion rolling towards Koru. The Kericho plateau forms the central part of the county sloping gently from 2,500m to about 1,800m above the sea level.
The county is surrounded by Tinderet Hills to the North and to the North-East is the Mau Escarpment and between them is the gently rolling land which forms Londiani hills (Tuluap-sigis). The central part of the county rises eastward towards 3,000m above sea level. The county is well drained with a good number of rivers that include Chemosit, Kiptaret, Kipsonoi, Timbilil, Maramara, Itare, Nyando, Kipchorian and Malaget. Some of these rivers are characterized by rapids and falls which could be harnessed for hydro-electric power generation. Some of the rivers with the waterfalls include Maramara, Itare and Kiptaret.
Kericho County lies in the Lake Victoria Basin. Its geology is characterized by volcanic rocks as well as igneous and metamorphic complexes. The county is predominantly underlain by tertiary lavas (phonolites) and intermediate igneous rocks. A small part of the county is dominated by undifferentiated basement system rock (granites), volcanic ash admixture and other prolific rocks.
The hilly nature in some parts of the county encourages soil erosion. This problem is however minimized by the presence of a dense vegetation cover, except in a few areas like Sigowet in Soin-Sigowet sub-county, Chilchila in Kipkelion west and partly the lower zones covering Koitaburot in Ainamoi sub-county.
The county enjoys favorable climate and receives relief rainfall, with moderate temperatures of 170C and low evaporation rates. Temperatures range between 100C - 290C. The rainfall pattern is such that the central part of the county, where tea is grown, receives the highest rainfall of about 2,125mm p.a while the lower parts of Soin and parts of Kipkelion receive the least amount of rainfall of 1,400 mm p.a.
The county experiences two rainy seasons: the long rainy season between April and June and the short rainy season between October and December. The dry season starts in January and progresses through March although weather shocks have changed the patterns. The variations in the temperatures and rainfall are mainly determined by the altitude of the place.