The WHO had previously warned that nearly 100,000 people in Somalia were facing catastrophic levels of hunger due to the worst drought to hit the region in 40 years.
According to the study released on Monday, between 18,100 and 34,200 people could die from the consequences of drought in Somalia in the first six months of this year.
Extreme weather could have led to 43,000 "additional deaths" last year compared to the drought in 2017, the study added, adding that half of the victims would be children under five.
This document was commissioned by the UN children's agency UNICEF and WHO and produced by the London School of Hygiene and Tropical Medicine and Imperial College London.
"We are in a race against time to prevent deaths and save lives," said Mamunur Rahman Malik, WHO Representative in Somalia. "The cost of our inaction would mean the deaths of children, women and other vulnerable people."
Five consecutive water-scarce rainy seasons in parts of Kenya, Ethiopia and Somalia have killed millions of livestock, destroyed crops and forced more than a million people from their homes in search of food and water.
Meteorologists expect a sixth rainy season to be equally desperately short of water, heightening fears of an unprecedented humanitarian catastrophe on the horizon, particularly in Somalia.
The country was hit by a famine in 2011 that killed 260,000 people, more than half of them children under the age of six, in part because the international community did not react quickly enough, according to the UN.
In 2017, more than six million people in Somalia, more than half of them children, were in need of assistance due to a prolonged drought in East Africa. But early humanitarian action averted famine that year.
© 2023 AFP