Naivasha has two dry seasons and two wet seasons, following the standard Kenya highland pattern. The main dry season runs from late June through October and is the most reliable time to visit — days are clear, the escarpment roads are in good shape, and the hiking on Longonot is at its best. The short dry season from January to mid-March is also good.
The long rains (March to May) make the Longonot and Hell's Gate tracks muddy and can make the escarpment road slippery, though the lake and its birdlife are good year-round. The short rains (November to December) are generally lighter and less disruptive.
Temperatures at this altitude (around 1,890 metres at the lake) are moderate: warm days of 20–28°C and cool nights. Bring a layer for evenings and early morning lake trips.