Why Kenya's Lake Victoria region gets so much lightning, and what officials advise

Why does the Lake Victoria region get so much lightning? Because the lake itself sets off thunderstorms. At night the land cools while the lake stays warm, breezes blow from the shore toward the water and meet over the lake, and the air is pushed upward into the towering clouds that produce lightning. A NASA satellite study of world lightning, published in May 2016, put six of the top ten sites in Africa, and the majority of the hotspots were by Lake Victoria and other lakes along the East African Rift Valley.

The Kenya Meteorological Service Authority (KMSA) has issued a heavy-rain advisory for 45 counties, The Star reported on 27 October, citing the Kenya News Agency. The advisory expects more than 20 mm of rain in 24 hours in some areas from 24 to 28 October, strongest from 26 to 28 October and easing by 30 October. It covers parts of the Coast, Northeastern, the highlands west and east of the Rift Valley, the Central Highlands including parts of Nairobi, and parts of the Southeastern Lowlands.

Lightning is a giant spark of electricity, the US National Weather Service says. Inside a thunderstorm, collisions between the different kinds of precipitation in the cloud give the particles an electric charge, and the ground below becomes charged too. At first, air acts as an insulator between the opposite charges. When the difference grows too large, the insulation breaks down and the electricity discharges in a rapid flash.

The ranking comes from NASA's 2016 work. Richard Blakeslee, project scientist for the Lightning Imaging Sensor at NASA's Marshall Space Flight Center, worked with lightning researchers at the University of São Paulo, the University of Maryland, NOAA and the University of Alabama in Huntsville to build a very high-resolution dataset from 16 years of space-based observations. The study appeared in the Bulletin of the American Meteorological Society, and NASA published its release on 2 May 2016. The top-ranked site was Lake Maracaibo in Venezuela, at an average of about 233 flashes per square kilometre per year.

The ranking counts flashes, not casualties. At Lake Maracaibo, NASA said, storms commonly form at night as mountain breezes develop and converge over the warm, moist air above the lake.

NASA's Earth Observatory explained the Lake Victoria storms in an article of 10 September 2020, updated on 31 January 2026. The storms, it said, are due to "a combination of the lake's location, size, and nearby topography." By day, breezes flow from the relatively cool lake toward the hotter land, where the air rises and can form storms. The process reverses at night: the land cools but the lake stays warm, breezes blow toward the lake, the air masses converge over it and rise, and the storms there become intense and frequent.

The same page says these violent nighttime thunderstorms kill roughly 3,000 to 5,000 fishermen a year. That figure covers storm deaths in general, not lightning alone.

The Kenyan advisory tells residents to avoid sheltering under trees or near grille windows to reduce exposure to lightning strikes. The National Weather Service gives the same warning about trees. Its myths page says being underneath a tree is the second leading cause of lightning casualties, and that it is better to get wet.

The Weather Service's rule is "When Thunder Roars, Go Indoors." If you hear thunder, it says, you are likely within striking distance of the storm, and there is no safe place outside when thunderstorms are in the area. Substantial buildings and hard-topped vehicles are safe options; rain shelters, small sheds and open vehicles are not. People should stay in safe shelter at least 30 minutes after the last sound of thunder.

For anyone caught outside with no shelter nearby, the Weather Service says to get off hills and mountain ridges, get out and away from ponds, lakes and other bodies of water, and stay away from objects that conduct electricity, such as barbed wire fences and power lines. It says never to lie flat on the ground and never to shelter under an isolated tree. Crouching, it says, does not make you any safer outdoors.

Clear skies are no guarantee. According to the Weather Service, "bolts from the blue" can strike 10 to 15 miles (about 16 to 24 kilometres) from the thunderstorm.