For that, super common to bike even in the winter. After all, you're already bundled up and will probably stay warmer just because you'll be outside for less time.
Anecdotally, I know a lot of women who ride bikeshare bikes for the 5-6 blocks it takes them to get home from the subway in the early-sunset months as a safety precaution against sexual harassment.
https://member.citibikenyc.com/map/
I mean they're not evenly distributed according to a perfect pattern or anything, but there's generally a bike within an avenue and a few streets.
Edit: As for summers, I've regularly biked in Texas throughout the summer over many years (I've lived without a car quite a bit in Austin). The peak of the day is rough, but the usual commuting hours aren't too bad. New York has nothing on Texas summers.
apart from that i guess you just have to ride carefully, but you the same applies to driving a car on icy roads.
Don't know why I find this double negative so disturbing. Seems so unnecessary.
but it's nice 7-8 months out of the year!
The biggest problem I have with biking in the winter is when it gets brutally cold, which doesn't happen that often, hardly at all in the past few years. There was this one particularly horrible winter several years back when it was terribly cold for weeks on end, and that was rough.
There are automated bike counters in certain places (e.g. bridge crossings), but I haven't been able to find the data for winter months. Citi bike data is probably a pretty good proxy, though. It's in the report I linked and in sibling from apaprocki
[0]: https://www1.nyc.gov/html/dot/downloads/pdf/cycling-in-the-c...
You can have a sense of it by checking with Google Maps street view on different places in Manhattan. It seems that there are way more cars and pedestrians than bike riders in most places.
Cyclists will deal with bad weather or bad infrastructure, but not many will deal with both at the same time. The solution is good infrastructure.