It's Friday.
Looking at 3 different forecasts, they all show around 10-12C and dry conditions for Sunday. Admission is to Highgate is £10. I have not booked in advance and was planning to take a self guided tour, which should be easier to purchase on the day.
Shall we go ahead and meet at London Bridge Station around 10AM on Sunday?We can take the Northern line from London Bridge, so if we meet on the lower concourse, near to Pret a Manger.