When you tried jumping it, did the clamps spark when you connected them?
They will only spark when they are transferring current. If the battery is fully charged when you connect, no spark. If the battery is drawn down, then they will spark. Do you have a volt meter? Real good tool for this kind of issue. My guess is that you have a weak/dead battery. Even if you just replaced it, doesn't make it good. For a car to suddenly not crank when the temperature drops is nearly always a bad battery. If it is recently replaced, then you most likely have a problem in your charging system, although it is not unheard of to get a defective battery, depending on what and where you bought. Check for loose wires on the battery, on the alternator, and on the starter. Starter could also be an issue, drawing too much current, then when the cold strikes and your battery loses some of it's cold cranking amps, it can't overcome the impedence of the starter.
First thing I would do if I did not have a meter would be to actually switch the battery with one that I knew was good. (ie from a different vehicle)
If the car starts, then you know that the battery is at least part of your problem. If it doesn't, then you can move to the next step.