Horses for courses I guess. It really comes down to a person’s expectations and tailoring their night out in London. Whereas in NYC where essentially every nighttime establishment closes as 4am. In London it really comes down to type of place and location.
Pubs can be anywhere from 11pm to 2am. Bars anywhere from 12am to 3am. Clubs almost always go from 4am to 6am (and sometimes longer). In London you just have to do a bit more homework but I find the club scene better while the late night cocktail lounge bar scene to be lacking.
The weather itself is fine. It doesn’t get super cold (rarely snows) and doesn’t get super hot except for a couple heat waves. I’m from California and got used to the temperature fairly quickly.
The worst thing is the constant gloom and darkness. It’s very often overcast so you feel you never get the sun and many people supplement with vit D. And the winters are pretty bad due to the short days. London’s latitude is higher than nearly every major North American city (on par with Calgary) so the sun sets around 3-4pm for months at a time.