Cold-weather battery failure is the #1 roadside call from November through February. Marginal batteries that survived fall finally die. The pattern is so predictable that dispatch surges capacity for the first hard freeze each year.
Cold reduces battery capacity. At 32°F a healthy battery loses about 35% of its cranking amps. At 0°F it loses 60%. A battery that was 'fine' in fall may not have enough output to crank a cold engine in winter.
Cold also thickens engine oil, increasing the cranking load. So the battery has less output while needing to do more work — a double squeeze.
Salt corrosion compounds the problem in cold-weather markets. Road salt eats battery terminals from below. Clean terminals annually and apply anti-corrosion compound.
If your battery is over three years old in a cold-weather market, test it in October. Auto-parts stores test free in under a minute. Below 75% capacity means replace before December.