Sarek National Park in November

June through August — that's your window. Even then, you might hit snow in early June or late August. July offers the warmest weather and 24-hour daylight, but also the most mosquitoes. Locals prefer late August when bugs die down and autumn colors paint the tundra. Here's the reality: summer temperatures range from 5-15°C, and weather changes fast. I've seen sunshine turn to sleet in 30 minutes. The midnight sun lasts from late May through mid-July, giving you endless hiking hours but messing with your sleep schedule. Winter? Only for experts with serious cold-weather gear and avalanche training.