Over the past 50 years, recorded disasters have increased five-fold, thanks in part to climate change.
The study warns that one in three people on Earth are not adequately covered by warning systems.
The numbers of people in need after natural disasters could increase by 50% over the next decade.
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The State of Climate Services 2020 has been produced by experts from 16 international agencies and financial institutions, and co-ordinated by the World Meteorological Organization (WMO).
Over the past 50 years, it says, some 11,000 disasters involving weather, climate and water-related hazards have occurred claiming two million lives and causing more than $3.5 trillion in economic losses.
In 2018, around 108 million people sought help from international agencies to cope with natural disasters.
The authors of the new report say that by 2030 this number could increase by 50% at a cost of around $20bn a year.
Effective early warning systems are key says the study - And the researchers who have compiled it are calling for a change in emphasis from simply forecasting what the weather will be, to showing the impact of that weather system.
Good quality warning systems are critically needed in the least developed countries and in small island states.
These countries have lost billions to weather and climate related disasters over the past five decades.
Around 70% of the deaths connected to these disasters occurred in the poorest nations.
Yet according to the WMO, just 26% of weather observation networks in Africa meet their standards.
The advent of the coronavirus has made the building of early warning systems more difficult the report says.