Heatwaves have increased in magnitude and frequency in recent years. The 2021 IPCC report states that evidence of observed changes in extremes such as heatwaves has strengthened since the fifth assessment report from 2014.
In Europe this summer hot extremes affected several countries. Researchers in Finland have looked at the excess number of deaths during the summer of 2021 in Finland.
Excess mortality
About 400 heat-related excess deaths took place in Finland in the summer of 2021, according to a preliminary analysis. This estimation is based on preliminary weekly statistics on deaths and the baseline is defined as a seasonal 5-year average of deaths in 2015, 2016, 2017, 2019, 2020.
– The health impacts of the heatwave we had in 2021 had about the same magnitude as when the previous major heatwave took place in Finland, which was in the summer of 2018 (omitted from the baseline), says Reija Ruuhela, climate expert at the Finnish Meteorological Institute (FMI).
The heatwave in 2021 was well predicted, and FMI issued timely heat warnings. The heatwave lasted about 4 weeks and the highest maximum temperature recorded during the period was 34 ֯C in July 15th in Heinola, in Southern Finland.
Lack of official heat action plan
In the figure we present weekly number of deaths in Finland together with the 7-day average of population weighted maximum and minimum temperatures over Finland, which smooth out substantially the daily and local temperature variations, but can be considered to represent population level exposure to the heat stress.
Figure: The figure shows weekly number (columns) of all-cause deaths during summer 2021 (June to August) in Finland. Maximum (red curve) and minimum temperatures (blue curve) are weekly averages for the whole Finland calculated as population weighted values from FMI gridded temperature data.
– Currently there is no official heat action plan for health care in Finland. However, public heat warnings typically trigger media attention, which increases public awareness of heat-related health risks and may also trigger some local activities in health care to mitigate adverse health effects, says Ruuhela.
People acclimatize into the typical climatic conditions where they live, therefore, in Finland heat-related mortality can be found in thermal conditions that can be considered still as “comfortable” compared to countries in Southern Europe, like Greece.
Sources: Meteorological data, The Finnish Meteorological institute; Death and population data, Statistics Finland.
In EXHAUSTION we study impacts of heat stress and contribute development of impact-based forecasting for the needs of the health sector. Reija Ruuhela is part of the team from the Finnish Meteorological Institute.
Helsinki. Photo by Nicolas Messifet/Unsplash.
