El Niño, a climate phenomenon originating thousands of kilometres away in the tropical Pacific Ocean, is expected to influence Kenya's weather significantly in 2026. Characterised by a warming of the central and eastern Pacific Ocean, El Niño disrupts normal ocean-atmosphere interactions, altering global weather patterns, including those in Kenya.

How El Niño Develops

Typically, easterly trade winds push warm surface waters westward across the Pacific, allowing colder waters to rise in the east. During El Niño, these winds weaken, causing warm water to shift eastward and warm the central and eastern Pacific. This shift affects atmospheric circulation, disrupting rainfall and temperature patterns worldwide.

Projected Impact on Kenya

The World Meteorological Organization reports an 80% chance of El Niño conditions between June and August 2026, with over 90% likelihood extending through November. Forecast models suggest a moderate to strong event, raising concerns about its effects on Kenya’s diverse climate zones.

The Kenya Meteorological Department (KMD) has identified 18 counties at high risk of adverse impacts such as flooding, infrastructure damage, and livelihood disruptions. However, rainfall distribution is expected to be uneven:

  • Highlands west of the Rift Valley, Lake Victoria Basin, Rift Valley, and Northwestern Kenya: Near-average to below-average rainfall.
  • Coast region: Near-average to above-average rainfall.
  • Highlands east of the Rift Valley, including Nairobi, parts of Southeastern lowlands, Marsabit, and Taita Taveta: Occasional cool, cloudy conditions with light rains.
  • Southeastern lowlands and Northeastern region: Generally sunny and dry.

Mean temperatures are expected to be warmer than average across most parts of the country.

Looking Ahead

The most critical rainfall period will be the October-November-December season, with KMD forecasting a 90-96% chance that El Niño-related rains will persist through the end of the year. Acting director Edward Muriuki emphasises that forecasts will be updated as new data emerges and encourages the public to stay informed through official updates.

Additionally, Kenya’s climate outlook considers the Indian Ocean Dipole (IOD), currently neutral, which can modulate El Niño’s effects. A positive IOD combined with El Niño often enhances rainfall over Kenya during the key rainy season.

Understanding El Niño's complex ocean-atmosphere interactions is vital for effective preparedness and response. Kenya continues to monitor these developments closely to mitigate risks and protect communities vulnerable to extreme weather events.