Summers in Finland are short but sweet. For three brief months, from mid-June to mid-September, temperatures soar as high as 30C and the Nordic forests bask under baby blue skies for up to 24 hours a day. After icebox conditions and perpetual darkness through the long months of winter, Finns embrace the summer with gusto. Lakes echo with the splash of swimmers and kayak paddles, and whole cities decamp to the countryside for lavish family feasts, fuelled by seasonal treats like crayfish, lingonberries and wild mushrooms. Recharging your vitamin D levels is one reason to join the summer celebrations; Juhannus (midsummer) is another. Held each June on the closest weekend to the longest day of the year (this year from 22 to 24 June), midsummer is Finland's most enthusiastic party -- an excuse for lakeshore bonfires, midnight airshows, drinking games, skinny dipping, saunas and all-you-can-eat banquets of grillimakkara (grilled sausages) served with mustard and the season's first new potatoes. Cheese is another midsummer staple, a legacy of the upsurge in milk production that followed the cows’ migration to summer pastures, and at family picnics you may encounter the curious Juhannusjuusto, cooked cheese curds served cold, sprinkled with sugar. For dessert, nature provides. From Åland to Lapland, wild berries paint the pine forests in Pointillist polka dots throughout the summer. City dwellers flock to the forests in July to harvest bilberries, wild raspberries, tart red lingonberries, wild cranberries and cloudberries – little clusters of orange bobbles that do indeed resemble tiny clouds. Juhannus may be the biggest feast, but Finland's love affair with wild food lasts all summer long. From June to September, you will be bombarded by tantalizing seasonal delicacies – wild mushrooms, nettle pancakes, bilberry pies, kiisseli (wild berry soup) -- and menus that change almost daily as new ingredients appear on the forest floor. Here are our favourite ways to immerse yourself in Finland's wild-food bonanza. Crayfish parties The Swedes were responsible for introducing the tradition of Rapujuhlat – riotous crayfish parties lubricated by liberal servings of schnapps – but this freshwater feast has spread far beyond Finland's Swedish-speaking enclaves. From August to September, families gather at kesämökit (summer cottages) across the country for no-claws-barred crayfish feasts, with huge vats of freshly-boiled crayfish, bottomless schnapps, and raucous songs and toasts to honour this crown-prince of crustaceans. Traditionally, crayfish tails are plucked from their shells and slipped onto a slice of buttered bread with a sprinkling of dill and a squeeze of lemon. Freshness is the key to the Rapujuhlat feast – the journey from lake bottom to party plate should be measured in hours, not days. In season, villa companies like Silverskär in the Åland archipelago offer crayfish fishing trips so you can accompany the delectable crustaceans on their final journey to the table, but you can make your own arrangements at lakeshore boat jetties, particularly in Swedish-speaking areas around Helsinki, Åland and Vaasa. If you cannot secure an invite to a crayfish party, Ravintola NJK in Helsinki is a commendable second-best. Set in a handsome copper-roofed villa on Valkosaari island, overlooking Helsinki harbour, NJK is feted as the capital's best crayfish restaurant, serving up more than 30,000 of these fire-engine red crustaceans every season. Try them in fennel broth, stirred into risotto, or the traditional way, boiled on buttered bread. Bursting berries In Finland, berry collecting is open to everyone. The right to roam and the freedom to forage are enshrined as “Everyman's Rights” in Finnish law. As long as the wild food in question is not from a protected species, anyone can comb the forests for luscious lingonberries, tart black bilberries, sunset-hued cloudberries, wild cranberries, raspberries and strawberries – just head to the woods from July to September. Finland boasts an impressive 23 million hectares of forest, covering 74.2% of the country. The uninhabited forests of Kainuu, accessible from the city of Kajaani, 460km northeast of Helsinki, are a good place to start – just be aware that you will be competing for berries with wolverines and wild bears! Mushroom season Not all Finns who head into the forest with baskets are after sweet berries; June to September is also prime season for golden chantarelles. Sprouting on the roots of birch trees from the Gulf of Finland to the south of Lapland, these fluted fungi are rated alongside morels and truffles by mushroom aficionados. Rich in vitamin D, potassium and iron, delicately-flavoured chantarelles are the magic ingredient in kanttarellikeitto, a rich traditional soup prepared with butter, parsley and thick cream. Foraging for chantarelles is probably best left to those who can tell the difference between fabulous fungi and deadly toadstools. Instead, sit back and let an expert chef transform the golden caps into taste perfection. At sleek Helsinki eateries like Chez Dominique and Ravintola Savoy, you will find chantarelles simmering in fragrant sauces, sprinkled over herb-glazed lamb fillets or frothed up into air-light foam. Summer in a single location If you cannot make it to the wilds to harvest nature's bounty, why not let Finland's seasonal food come to you? At Kauppatori, the bustling market square that sprawls along Helsinki's South Harbour, traders sell everything from packed-to-travel pickled chantarelles to farm-fresh peas-in-the-pod and cloudberry preserves. It is touristy, but in between the stalls selling reindeer skins and Sarah Lund-pattern sweaters you will find every wild food that grows under the Finnish sun, sold by the litre jug.