Why is the weather so miserable in Sweden (and when will it get better)?

The Swedish summer got off to an unusually warm start, but since then temperatures have cooled down significantly and few days have gone by without at least one rain shower. When will the sunny weather return to Sweden? https://www.thelocal.se/20200713/why-is-the-weather-so-miserable-in-sweden-and-when-will-it-get-better