The agency cautioned however that those roughly 700 additional deaths cannot necessarily be directly attributed to the heat. Significant increases in mortality during the summer were only seen in the older age groups.
The 700 additional deaths occurred during the period of June 18th through September 2nd, or weeks 25 through 35 to use the Swedish method of numbered weeks.
The highest mortality rates were during the week of June 25 through July 1st and the period of July 16th through August 5th, according to the agency’s figures.
The summer months also saw a marked increase in the number of vibriosis infections, caused by Vibrio bacteria that live in coastal waters. While an average summer brings around 20 cases of vibriosis, there were 131 this summer.
“A probable explanation for the summer’s increase in vibriosis infections is that our bathing waters were unusually hot for an unusually long time,” epidemiologist Anders Tegnell said in a National Health Agency press release.
The summer of 2018 set numerous weather records in Sweden, beginning with the hottest May on record and the hottest June in 100 years. That was followed by one of the hottest months of July ever recorded in several places across the country, including Stockholm’s average temperature of 22.5C, which was the highest-ever average temperature in the country and several degrees above normal. That month also saw the outbreak of what was described as the “most serious” wildfire situation of modern times.
Up until August 28th, when the weather started to cool down, the north had temperatures of 1-3C above normal and the south Sweden 2-4C. In most of southern and central Sweden, it was the warmest summer since records began, including in Uppsala (records began 1722), Stockholm (1756), Lund (1859) and Gothenburg (1860).
The National Health Agency said that survey results indicated that upwards of one-fourth of Sweden residents experienced some sort of heat-related health problem during the record-breaking summer but that a full 96 percent of survey respondents felt that they had been adequately informed on how to handle the heat wave.