Compare summer times in France and Britain?

Answer 1

France is a little warmer. The food more elaborate (most people say better.) The language gives you the feeling you are having an adventure.
More old small churches and old abbeys, and as many cathedrals.

England is likely to be a little wetter, but can have lovely weather too. The food is more familiar, and will be good most of the time.
People speak English but it might be with a strong, strange accent.
Many Cathedrals.

I like both countries, and have to say, except for the food, the language and the churches I think they are in the same class.
Both more than worth going, and spending as long as you like.
Both have a big town, London - Paris, and both have many smaller towns worth visiting.
And countryside in both is worth seeing, and rather inaccessible, unless you can use a car.
People are nice in both countries, if you reach out first, and are willing to break the ice.

So it is up to your sense of adventure, if you think you can handle the strange language, with the likelihood of better weather, (in the south, in the north it is much like south England) visit France.
Or do you go for familiar talk, and visit England.

Answer 2

You can check the time in France here http://www.a-taste-of-france.com/weather-in-france.html

Answer 3

Still one hour difference, summer or winter.