Paris or London in mid October

Is there any reason that you would pick Paris over London in October?

Either one would be a good choice, in the situation you describe.
Both are obviously "world class" destinations and filled with fascinating things to see that will make for a wonderful experience.

I don't think weather, school holidays, or other "extraneous" factors would particularly affect this decision for me.

Wendy I agree with both previous posts.. there is no factor here ( the dates) that really make a difference one way or the other.. both are great places.. both will keep you busy with lots to see and do.. I would just go with my heart.. ( my heart of course.. leans towards Paris, personal tastes)..

I could spin a wheel and be happy with either one however.

The time of year would not affect my choice between the two.

PS - If you have any questions about Israel, PM me.

Pick one or the other.. You can always do a day trip to either location on the Eurostar. It is 3.5 hrs from London to Paris. And spend the day.. I've done it before. Choose the city where you want to spend the most time. Have fun!

Asking whether you should go to London or Paris is like asking should you get chocolate or vanilla ice cream. Everyone has their own preference.

Choose the one you most want to see.

With young kids I would pick London as they love the museums, changing of the guard etc... With older kids, they love London AND Paris. For adults, both are great, although I enjoy the food more in Paris.