We will be in Paris from Sept 10-14th, Provence from Sept 14-18 and Lourrie Valley Sept 18-20th. Does the weather and tempertures change much between the areas of France? What is
it like in September in France will be need to pack jackets and is it still warm enough for summer skirts or capris??
Is there a website showing temps for the different areas and months?
I don't know about websites that show temps, etc. (I know they exist, I just don't know the address of one specifically).
Anyway, I lived in France for a year about 20 years ago. I can tell you that the weather is very similar to what you'd find in Seattle (if you have ever been here). In September, it is likely to be hot enough for skirts and capris.
I would recommend, though, taking a light jacket and some type of non-sandal shoes (such as a ballet flat) in case the weather is cool for a day or it rains.