The tradition of eating crayfish in August is more than 500 years old, but originally it was a pleasure for the rich. Slowly the tradition has spread, and it is now one of the biggest highlights in August.
The reason why the parties are held in August has to do with the fact that fresh crayfish are at their best at that time of the year. There is also another advantage: it is an ideal time of the year to sit outside and enjoy the (relatively) warm evenings and admire the starry sky that you don’t see during the early summer since it doesn’t get dark enough. If you know someone who has the fishing rights and can fish some crayfish: congratulations. If you don’t have that option and don’t know people who can invite you for a traditional crayfish party, then one of the great options in Stockholm is to go to the restaurant Ulla Winbladh. That is a traditional and prized restaurant on Djurgården near the Vasa museum. Between the 19th and 23rd of August they offer a three-course crayfish menu that starts with a chanterelle toast.
The easiest way to get there is by tram; take line 7 from the Central station in the direction of Waldemarsudde and get off at Nordiska museet. The ride takes about 7 minutes.