When to visit
One of the great things about Paris is that it is a lively city no matter the time of the year, and each season has its own charm. If you want t experience a quieter Paris (less traffic) then August is perfect! Most of the Parisians are gone on holiday. This means less people on the road, less traffic so a quieter Parisian experience.
The best time to enjoy what the Loire Valley has to offer is from May to October with a pleasant weather and plenty of activities available.