On a clear day it is customary to walk around the crater to the weather station that marks the volcano's highest point. Some send postcards from the summit post office.

The uncertainty arises mainly because weather stations were never intended to provide a climatic record.

One is the poor location of many weather stations.

Existing studies of climate sensitivity mostly rely on data gathered from weather stations, which go back to roughly 1850.

It straddles the 80th parallel and was created as a weather station in 1947.