If you're after the sunniest month for a city break in France, July is usually your best bet. Across popular cities like Paris, Nice, and Lyon, July tends to bring the longest days and plenty of sunshine, with average temperatures ranging from 20°C to 27°C. It's a fantastic time to explore city parks, riverside walks, and outdoor cafés. Do keep in mind, though, that it’s peak holiday season, so attractions may be busier than at other times of the year.