My front door latched fine all summer and then turned into a draft machine in December. You could feel the cold air rolling in along the bottom edge, and the heating bill noticed. The door was not warped. The latch was fine. The gap was just there, every winter, like clockwork.

Why Winter Makes It Worse

Cold air contracts the wood and the frame, and in humid summers the door swells and fits tight. Winter gaps appear because everything shrinks. If the door locks and latches but you can still see daylight at the edge, this is your problem.

The Fix That Takes Ten Minutes

1. Check the hinge screws first. Loose hinges let the door sag and open a gap at the top or bottom. Tighten every screw on both hinges.
2. If the gap is on the hinge side, remove the middle hinge screw and drive in a longer screw, 2 to 3 inches, so it bites into the wall framing. This pulls the door back into position.
3. For the gap between the door and the jamb, add self-adhesive weatherstripping foam to the jamb stop. It costs a few dollars and takes thirty seconds to stick on.
4. For the bottom gap, install a door sweep. It is the single best draft fix per dollar that exists.

The Strike Plate Trick

If the door latches but rattles or sits loose when closed, the problem is the strike plate. The little metal plate on the frame is usually the last thing anyone checks. Bend it a hair toward the door, or add a shim behind it, and the latch will sit snug instead of loose.

What Not to Do

• Do not crank the weatherstripping too thick. If the door will not close, you overdid it. Start thin.
• Do not ignore a sagging door. A hinge screw fix is temporary if the hinge itself is shot.
• Do not caulk the gap shut if you live somewhere humid. You need the door to breathe with the seasons.

The long screw trick fixed my front door in about four minutes. No more cold spot on the floor, no more draft whistling at the edge, and my heating bill dropped a little too. If your door only misbehaves when it gets cold, start with the screws before you buy anything fancier.