As fboab mentioned, we had to get serious with gloves last winter, after we had a
SITUATION on the "When I'm 64" 200. It was cold (around 2C) with moderate rain and wet snow, all day. I was wearing these (Altura Nightvision windproof):
Untitled by
Pelotonhound, on Flickr
My hands got so cold I couldn't work the brakes and she had to invoke Stoker Emergency Braking Privileges to stop us. Not fun. Trust us to pick the coldest winter in 40 years to mount an Audax points chase. So fboab bought me gloves.
Specialized Radiants (The "Arctic" ones):
Untitled by
Pelotonhound, on Flickr
Specialized Sub Zeros (The "Antarctic" ones):
Untitled by
Pelotonhound, on Flickr
The Radiants are fine for most 0c conditions. It takes a goodly while for water to penetrate, but it does eventually. I wore these on the
Green & Yellow Fields White & Frosty Fields 300 where it got to -5c overnight, and they weren't up to it - I had cold hands, and had to use disposable hand-warmers too. In conjunction with hand-warmers - I was fine. If I'd had these on the "When I'm 64" ride, I think I'd have been OK.
I've only used the lobsters a couple of times. Nothing gets through them - they're toasty warm. I don't think I've worn them in the wet, only cold - but they handle sub-zero without any problem, and I'm able to operate STIs just fine - something I was concerned about given the reduced fingerage. I should have worn these on the
Green & Yellow Fields White & Frosty Fields 300.
Both the Radiants and the Sub Zero (liners) have conductive pads so you can operate your iStuff/GPS touch screen without removing them - useful if that's important to you.
ETA: I would disagree with Kim (which hardly
ever happens). A degree of waterproofness is very important if you are riding for a long time in the wet. When your gloves become wringing wet in cold conditions, it's very bad - at least it is for me. I had to go to the docs after the When I'm 64 200 as I had some tissue damage to my fingers, which he said "Looks a lot like frostbite".
ETA 2: I wore the Specialized Radiants during the day on our Easter Arrow, and the lobsters overnight. During the day it was dry but cold, around 0c. During the night it was very cold (-5c) and snowy later. The only time I had cold hands was when getting started after a control stop - and that always happens; it's a circulation thing - I soon warmed up again.