Four climbers dead and five critical after night stuck outside in Swiss Alps

The climbers were caught off-guard by high winds, snow and bitter cold in the Swiss Alps. Photo / AP file

An unexpected snowstorm coupled with high winds has killed four climbers in the Swiss Alps and left five others in critical condition after they became trapped overnight and couldn't reach shelter.

A total of 14 hikers from France, Germany and Italy were left stranded in the Pigne d'Arolla region, police in southwestern Valais canton said.

Authorities deployed seven helicopters as part of rescue efforts.

The climbers were caught off-guard by high winds, snow and bitter cold, and were forced to spend the night outdoors, Valais police spokesman Markus Rieder said.

Several of those rescued were suffering from hypothermia, and were rushed to area hospitals.

Police said three people died in hospital, and another apparently was killed in a fall.

Five others were hospitalised in critical condition. Details on the other five hikers that were part of the group weren't immediately provided.

Police said the climbers were trying to reach the Vignettes hikers' hut at 3157m in the Alps.

Europe has experienced turbulent weather over the past several weeks, with unseasonable spells of hot and cold.

In Germany, firefighters pumped rainwater from basements and clearing flooded road tunnels after a storm swept through parts of western Germany overnight.

Germany's far-west Aachen region was the hardest hit, with rescue services receiving hundreds of calls. Aachen police say nobody was harmed in the storm.

France, Belgium and Luxembourg were also affected by heavy rain and hail - weather that is more often seen during the summer than the spring.

Recent days have seen unseasonably warm weather in parts of western Europe. The storm was moving north towards Denmark.

- AP

Beautiful but potentially deadly, conditions in the Swiss Alps can change in an instant. Rescue teams respond to over 1600 calls a year from hikers, climbers and skiers looking for adventure#EarthsNaturalWonders pic.twitter.com/38dCeA8BM3

— BBC Earth (@BBCEarth) March 7, 2018