The Short Answer May, June, September and October. These months give you long days, almost all the tourism businesses are open, the crowds of July and August are avoided, midges are not at their most prolific and even the weather is pretty decent.

The best months to visit Scotland are generally May, June, and September. May and June are particularly prized because they offer the driest weather and the longest daylight hours (up to 17 or 18 hours of light), which is ideal for exploring the rugged Highlands and the Isle of Skye. These months also occur just before the peak of the "midge" season—the tiny biting flies that can be a nuisance in late summer. September is another excellent choice, as the summer crowds begin to thin, the weather remains relatively mild, and the landscape begins to turn into a spectacular tapestry of purple heather and golden autumn foliage. For those interested in cultural festivals, August is the "best" but also the busiest and most expensive time, as Edinburgh hosts the world-famous Fringe Festival. While winter (December to February) is the cheapest time to visit, many rural attractions and remote roads may be closed due to snow, making the late spring and early autumn windows the most balanced choice for weather, accessibility, and scenery.