I am flying to Glasgow early May for two weeks and then one week in London. I haven't been in 20 yrs.

I am flummoxed by the weather. Of course I have looked at the long range forecast but friends have told me they were very cold and damp when they visited.

I was planning to pack ponte pants and skinnies for day time and have tall boots for that. But I have some ankle length trousers for days I need to look 'tidy' but if is cold what is my footwear with ankle pants? I don't want cold feet.
Any ideas?

I was thinking moto like boots but it is not the season to buy, I see lots of flats and sandals.