Temperature holding up at 16°C or just above in parts of London this morning/overnight. Challenging the UK highest minimum temperature record for April of 15.9°C. However, I’m not sure it would count as an official record due to the 09:00 - 09:00 reporting period, with temperatures early yesterday having been lower than 15.9°C.
Edit: Actually, it was colder late last night so it won’t be a record, anyway. Still, an impressively mild start to the day.