BERLIN — The La Nina climate phenomenon has developed and is expected to last into next year, affecting temperatures, precipitation and storm patterns across the world, the U.N. weather agency said Thursday.

A La Nina usually means a more active Atlantic hurricane season, with more and perhaps stronger storms.

The World Meteorological Organization in Geneva said La Nina, characterized by abnormally cold sea surface temperatures in the eastern Pacific Ocean, is “expected to be moderate to strong” this year.

The global declaration of a La Nina event is used by governments to help plan responses in vulnerable sectors like agriculture, health, water resources and disaster management, the WMO said.

La Nina Typically Brings More Rain to the North of the Continent and Less to the South

This year’s La Nina is expected to bring drier than usual conditions to East Africa during the planting season, which the U.N. weather agency called “a further worrying development which may add to the food security challenges in the region.”

In North America, La Nina typically brings more rain to the north of the continent and less to the south.

Elsewhere, it is expected to bring wet conditions across large parts of South East Asia and Australia.

South America is expected to see above average rainfall on the northern part of the continent and below average on much of the south.