Ask when to visit almost anywhere and you will get a month. The honest answer is usually a fortnight — and not the same fortnight for every traveller. “Best time to go” compresses three different questions into one word, and a plan is better when it keeps them apart.
Best for the weather is a different question from best for you
The weather answer is the easy one: temperature bands, rain patterns, when the passes open. It is also the answer everyone else has already read, which is why the weather-perfect weeks are the crowded, expensive ones. Best weather and best value sit on opposite sides of the same dates almost everywhere.
So when a plan of ours lands a week either side of the textbook window, that is not a compromise. Shoulder weeks are usually the deliberate choice: most of the weather, a fraction of the queue, and hotel rates that have not yet heard the season has started.
The calendar has opinions of its own
A national holiday can close the museums you came for or turn them into the best week of the year, depending on the country. School terms move whole populations. A festival can double hotel prices in a city and leave the town an hour away untouched. None of this shows up in a climate table, and all of it shows up in your trip.
This is why we ask when you can travel before we praise any month. A retired couple and a family tied to school holidays should not be sent to the same weeks, whatever the weather chart says.
What we actually optimise
Not the perfect week — the least-regret week inside the time you actually have. If your only window is August, the question is not whether August is ideal. It is which destination makes August look like the plan all along.