Dr. MartensUnisex-Adult Embury Leather Chelsea Boot

Is the size of this boot uk sizing or us sizing? i'm looking for europe size 39 or us size 9 for these boots.

If my foot measures 24.5 cm, what size should I buy?

Would you recommend these boots for cold/wet weather?

What is the shaft height from the top edge of the rubber sole to the top of the boot at the ankle opening? How many inches is that?