"Nearly 9 million individuals were impacted by climate hazards in the last 12 months, with over 500,000 displaced by floods, drought, and other disasters," according to the IOM report.

"Roughly three in five of those displaced relocated elsewhere within their province of origin", with the western Herat and Farah provinces among the hardest hit, it said.

This week, 39 people were killed due to floods, hail and storms in southwestern Afghanistan, mainly in Farah, according to local authorities.

Afghanistan is among the poorest countries in the world after decades of war and is ranked the sixth most vulnerable to climate change, which is spurring extreme weather.

Drought, floods, land degradation and declining agricultural productivity are key threats, according to the United Nations.

Flash floods last May killed hundreds and swamped swaths of agricultural land in Afghanistan, where 80 percent of people depend on farming to survive.

"Over 11 million people in Afghanistan are at high risk of severe impacts from climate-induced disasters in the future," the IOM said.

The UN agency estimates that "climate-sensitive livelihoods, like subsistence farming, make up 73 percent of jobs in Afghanistan".

It added that "92 percent of villages have limited access to emergency services" and "96 percent lack resources for crucial measures like early warning systems and search and rescue."