Norway changes its definition of heat waves 

Heat wavePhoto: Håkon Mosvold Larsen / NTB

This summer, Norway will test out a new definition of heat waves. The new requirements will now require a longer period of heat to be classified as a heat wave. 

Previously, a heat wave has been defined as a temperature of 28 degrees or more over three days. But that is about to change.

The new classification requires a temperature of more than 28 degrees during the day over five days. At the same time, the night temperature can not go below 16 degrees in the same period.

“The change is from 3 days to 5 days running mean – of maximum temperature above 28 C, and now we include the minimum temperature as well (the night temperature does not go below 16 C in the running mean for the same 5 days),” climate researcher Helga Therese Tilley Tajet at the Division for Climate Services at the Norwegian Meteorological Institute told Norway Today via email. 

The reasoning behind the change

“The Meteorological Institute (MET) wanted to have a more strict heat wave index due to experience that the 3 days heat wave index happened too often. 

“This summer, we are testing if MET should start with a danger warning for heat waves. MET wanted to have an index for challenging heat that feels a little uncomfortable and happens approximately every other year. 

“Then we decided to include the minimum temperature during the night and extend the number of days,” Tajet added. 

She noted that the new definition would also help monitor future heat wave phenomena.

“This summer, the MET is testing if we should have a danger warning for heatwaves. We will evaluate that after the summer,” the climate researcher concluded.  

Robin-Ivan Capar is a contributor and editor at Norway Today.

Source: #Norway Today / #NorwayTodayNews

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