Kenya is entering a wetter-than-usual short-rains season, but the rains will arrive at different times across the country. For Nairobi and much of central and southeastern Kenya, the latest official outlook places seasonal onset in the second to third week of October.
The Kenya Meteorological Service Authority’s September 30 bulletin provides the following regional guide.
When are the rains expected?
| Counties or region | Expected seasonal onset | Expected end |
|---|---|---|
| Nandi, Kakamega, Vihiga, Bungoma, Siaya, Busia, Baringo, Nakuru, Trans Nzoia, Uasin Gishu, Elgeyo Marakwet, West Pokot, Kisii, Nyamira, Kericho, Bomet, Kisumu, Homa Bay, Migori and Narok | Continuing from September | Into January |
| Nairobi, Kiambu, Murang’a, Kirinyaga, Nyeri, Nyandarua, Laikipia, Meru, Embu and Tharaka Nithi | Second–third week of October | Into January |
| Machakos, Kitui, Makueni, Kajiado, Taita Taveta and inland Tana River | Second–third week of October | Into January |
| Mombasa, Kwale, Lamu, Kilifi and Tana Delta | Continuing from September | First–second week of December |
| Marsabit, Mandera, Wajir, Garissa and Isiolo | First–second week of October | First–second week of December |
| Turkana and Samburu | Third–fourth week of October | First week of December |
These are forecast windows, not guaranteed arrival dates for every neighbourhood or farm.
What is expected this week?
The shorter-range forecast, valid October 4–8, mainly predicts light to moderate rain in several counties.
For Nairobi, it lists light morning rain and night showers from Monday to Thursday, with sunny intervals on some afternoons. Mombasa is expected to receive a mixture of light and moderate showers. Turkana is forecast to remain largely sunny during the day throughout the period.
That distinction matters: a wet seasonal outlook does not mean heavy rain every day. A shower before the projected onset window also does not, by itself, establish that sustained seasonal rains have begun.
Why will the rains differ across Kenya?
The short rains develop as the tropical rain belt moves south across East Africa. Their strength also depends on ocean conditions and shorter-lived weather systems.
The national climate outlook identifies El Niño and the Indian Ocean Dipole as important influences. A positive Indian Ocean Dipole can enhance rainfall, particularly when it coincides with El Niño. Tropical cyclones and the Madden–Julian Oscillation can influence rainfall intensity over shorter periods. meteo.go.ke
This is why an “El Niño rains” headline cannot tell a farmer exactly when to plant or a commuter whether tomorrow’s journey will be wet.
The climate outlook expects generally fair-to-good rainfall distribution across much of Kenya, with poorer-to-fair distribution in Turkana and Samburu. It also notes that the short rains contribute more than 40 per cent of annual rainfall in several eastern and northeastern counties.
What should readers do with this information?
The monthly bulletin identifies both opportunities and risks: improved soil moisture and pasture, alongside possible waterlogging, flooding and transport disruption.
For farmers, the useful next step is checking county forecasts and agricultural advice before making planting decisions. For households and businesses, preparation should follow local flood advisories and the condition of nearby drainage, roads and rivers.
Seasonal forecasts help people plan ahead. Daily and weekly updates help them decide what to do now. The meteorological authority advises using both, with county-specific forecasts available through County Directors of Meteorological Services.
Forecast information checked on October 5, 2026. Onset dates are from the September 30 monthly bulletin; the short-range forecast covers October 4–8.
