For Tuesday the forecast says 26°C which is the same as 78.8°F. Best place to be is at the beach or as close to water as possible. A boat trip around and under the bridges of Stockholm is highly recommended too. But anyway you go except into the water you’ll be jealous of people like these who do not let anything get in their way to enjoy a good swim! And beware, already on Friday temperatures might drop below 20C° again!