Travelling from most locations, it is best to book your flight to Sweden during the month of January for the best deal, although there are other times of the year which offer great deals as well.
In general, most flyers find the cheapest time to book a flight to Sweden is about 60 days prior.
In general, booking your departure to Sweden for a Friday represents the best deal on airfare. Try to avoid a Sunday departure to stay away from the highest prices.
On average you can find the best deals on plane tickets to Sweden when looking for flights with morning departure times.