Danish winters have seen a significant temperature increase of three degrees Celsius since 1874, while summer temperatures have only risen by one degree Celsius. This discrepancy has puzzled climate researchers and is a topic needing further analysis.
The summer months in Denmark are perceived to be similar to those of three to five decades ago, supported by measurements showing a modest increase in summer temperatures compared to the more pronounced warming in winter, spring, and autumn. The oldest heat record in Danish weather history remains a summer record, set in June 1889 with an average temperature of 18.2 degrees Celsius. Furthermore, the average July temperature in the last decade was slightly cooler than the average from 1931 to 1960.
Several factors are proposed as explanations for this trend. Denmark’s coastal geography could be dampening summer temperatures due to the cooler sea. Increased rainfall, leading to greater evaporation, might also contribute to a cooling effect. Another potential explanation involves changes in the jet stream, which may be locking Denmark’s summer weather into more erratic patterns.
While there is disagreement in climate research about whether these fixed weather patterns result from human-caused global warming, such patterns may explain the extreme summer temperatures in Southern Europe. As an example, Southern Spain recently experienced near-record temperatures for May.
Despite the subtle impact of global warming on Danish summers, experts anticipate that the country’s heat record will eventually be broken. The current record stands at 36.4 degrees Celsius, established 49 years ago. Jens Hesselbjerg Christensen, a professor at the Niels Bohr Institute, believes a new heat record will occur within his lifetime.
Looking ahead, the temperature difference between Danish summers and winters is expected to decrease. The significant winter temperature increase has been attributed to reduced sea ice and snow cover, leading to greater heat absorption. With minimal remaining ice and snow to melt, future temperature increases are projected to be more uniform across seasons.