The Kenya Meteorological Service Authority (KMSA) has forecast light rains and showers in 36 counties across the country, starting from Saturday. Principal meteorologist Jemimah Gacheru advised Kenyans to follow forecasts from regional county offices of the Met service, as the department's five-day forecast indicates rain spreading to various counties.
According to Gacheru, the forecast should be used in conjunction with the daily 24-hour forecast issued by the department, and county-specific forecasts are available from the offices of the respective county Directors of Meteorological Services. The Met service has not declared the onset of the October-December rainy season, as it requires at least 20mm of rain within three consecutive days and no dry spell lasting more than seven days afterwards.
The forecast shows that Nairobi will receive light rain on Saturday, with moderate showers in the afternoon. Other counties expected to receive rain include Mombasa, Kwale, Kilifi, Tana River, Lamu, Taita Taveta, Garissa, Wajir, Mandera, Marsabit, Isiolo, Meru, Tharaka Nithi, and Embu counties. However, not all farmers should expect rain this weekend, as Turkana, West Pokot, Trans Nzoia, Uasin Gishu, Nandi, and Narok are forecast to remain generally dry on both Saturday and Sunday.
Some counties that remain dry on Saturday could receive rain on Sunday, including Nakuru, Kericho, Bomet, Kakamega, Bungoma, Busia, Migori, and Kisii. Charles Mugah, deputy director at the Kenya Meteorological Department, said this year's rainy season is being driven by the Indian Ocean Dipole (IOD) and El Niño. The IOD refers to the difference in sea surface temperatures between the western and eastern Indian Ocean.
Mugah explained that when waters on the western side, near Kenya, become warmer than those in the east, a positive IOD develops, bringing heavier rainfall to Kenya and neighbouring countries. He predicted that the IOD is currently neutral but is expected to turn positive from September, reaching levels close to those recorded in 2015, when Kenya experienced widespread flooding.
The World Meteorological Organization (WMO) said in September that El Niño is firmly established and is expected to become very strong towards the end of the year. The WMO and regional climate outlooks have also indicated a higher chance of wetter-than-normal conditions in the Greater Horn of Africa during the last quarter of 2026.
Edward Muriuki, acting director at the Kenya Meteorological Service Authority, emphasized that the forecast would only be useful if people acted on it early, saying "climate information must be understandable, relevant and actionable."
Key points
- The Kenya Meteorological Service Authority forecasts light rains in 36 counties, but cautions against mistaking this as the onset of the October-December rainy season.
- The onset of a rainy season is not simply the first day it rains, but requires at least 20mm of rain within three consecutive days and no dry spell lasting more than seven days afterwards.
- El Niño is expected to become very strong towards the end of the year, with a higher chance of wetter-than-normal conditions in the Greater Horn of Africa during the last quarter of 2026.
