Scotland is known for its rolling green hills and damp days. Like the rest of the country, Edinburgh has a temperate climate, which means the city has relatively chilly winters (though rarely below freezing during the day) and its share of stormy skies. That said, all seasons in Edinburgh are surprisingly mild and comfortable conditions generally exist for visitors from May all the way through September. And if you do want to travel in the winter, there’s plenty going on to keep you active and warm even if the mercury (or the snow) begins to fall. The world-famous Hogmanay festival is held around New Years and draws hundreds of thousands of Scots out of their heated houses for four days of street celebrations.

Meanwhile, an equally celebrated and undoubtedly warmer event, the Edinburgh Festival Fringe -the world's largest Festival of performing arts- takes place in August, alongside 7 other Festivals ranging from Jazz to performing arts and the world famous Tattoo. Many travelers choose to plan their trips to the city around this time to take advantage both of the Fringe and of the long, comfortable summer days—the last traces of daylight don’t vanish from the sky until well after 10 p.m. If you do want to visit Edinburgh during one of its big festivals, though, make sure you plan well ahead; hotel rooms and event tickets disappear quickly. 

BBC's Edinburgh Weather - 5 Day Forecast