> Check your battery first, no excuse if you can get to a store it's free to check.
> If no store nearby that does it find something that will.
> If not battery then the only things left are what natgashole said. On some cars
> it is easy while others is not and must remove a bunch before getting to the alternator.
> If easy i would try to do it yourself if not what is what don't remove a bunch
> to get to it have someone else do it.
Some auto stores can test the alternator in the car.
Given the age and the temperature outsife it's most likely the battery. The original description isn't clear and implied it might not be the battery.
Does the battery keep turning the motor?
Sam is right about the CCA. You can use a weak battery for a long time if it's not cold outside, but when the temps drop you need those CCA to turn the motor.