Looks like a grass snake and probably a female by the length. Hurdled one the other day down a footpath I was running along but it had the really distinctive yellow collar.
That one looks like it may be digesting something too shaolin?
Which part of Hull was it?
I know where you mean mate, ideal habitat really. Seems to be the heat that brings them out of hiding. When we had a pond the young were always falling in and having to be rescued.