Girls are at greater risk of dropping out of education when their schools are hit by heatwaves, storms or wildfires linked to climate change, the UN children's agency said on Thursday.
Unicef analysis suggested that one in 10 or more than 171 million students in 106 countries or territories had their education disrupted by extreme weather last year.
But the agency said girls were worst affected when schools were damaged, classes cancelled or education switched online.
"Girls are at greater risk of dropping out when climate hazards disrupt or close schools," it said.
"Damage to schools and sanitation facilities, displacement and lost family income can place additional caregiving and water-collection responsibilities on girls, said AFP.
"These pressures can also increase the risk of child marriage, making it more difficult for girls to return to class when schools reopen."
According to the analysis, storms were the most common cause of disruption and last year affected 109 million students around the world.
Floods hit at least 70 million while heatwaves disrupted schooling for some 50 million youngsters.
The overall figures for 2025 are down on analysis of the previous year, in which Unicef said nearly 250 million children in 85 countries -- one in seven -- were affected by climate hazards.
The agency said it had changed its methodology, basing its analysis on information from aid agencies and local media rather than government figures.
Unicef said about one billion or about half the world's children live in countries at very high risk of climate and environmental shocks.
Lost learning and the effects on literacy and numeracy could lead to lifetime income losses of at least $200 billion and worsen global inequalities, it estimated.
Most of the children come from low- and lower-middle income countries "where education systems often lack the resources needed to safeguard learning during climate-related emergencies", the study said.
Unicef urged governments and their partners to spend more on building new educational facilities to withstand climate and environmental hazards.
