Husband and I were in London in late Mayearly June this year . It was fantastic , although cold . Be prepared for that ! We are also from a warm climate desert southwest and although I thought I was prepared for the lower temps , I wasn ' t . The light layers I brought weren ' t enough and I ended up having to buy a jacket , hat , scarf , etc . As for your question about day trips , we did a day trip through a tour group to Bath , the Cotswolds and Stonehenge . We really loved it . Our favorite part of the tour was Bath , which you can do on your own easily by taking the train . It ' s a medieval city that is absolutely gorgeous and has amazing architecture . We ' re planning to go back there in June and spend a full day exploring . From what I ' ve looked up , it looks like trains between London and Bath run every half hour and only take about an hour and a half to get from one city to the other . ETA we stayed right near Trafalgar Square , and the location was ideal in terms of ease of getting around and being centrally located . We had two tube stations and two bus stops within a few minutes walk of our hotel , and we weren ' t far from the major sightseeing destinations . The place we stayed at was called Thistle Trafalgar Square . We were really pleased with our stay there and would recommend it .