Gary from Toronto has a 75 year old door with copper V strip weather-stripping that doesn't stop much wind any more. What to do?
Wooden outside doors tend to warp a bit with changes in the weather and with any direct sunlight on them, so you will probably find that the south facing door will warp more than the north facing door.
There are two places you need to weather-strip a door - the edge of the door, and the bottom, and in each case you have an option of a compression or a wiping type seal, or both.
The V strip or its modern equivalent, a vinyl door wipe in a kind of V shape, is attached to the frame and seals to the edge of the door as it wipes against it. The best of these come from a company called Schlegel. This is a type of sliding weather-stripping in that the door slides along it. It works well, but is always a problem where the door latch and lock take up space.
Compressive weather-stripping goes on the door frame and the door bumps into it. The best of these are magnetic for metal doors, or spring loaded for wooden doors. You can actually use both wiping and compressive weather-stripping and improve the draft tightness of any door.
Sealing the bottom of the door requires finding something that works with your particular type of door sill. Some sills use stops that the door pushes against, although you have to keep them clear of snow. Some door sills are wide and flat, allowing you to put sweeps on the door, avoiding the snow accumulation problem. The best of these is a U shaped piece that fits under the door and has a series of fins to lock against the door sill. You usually have to cut a bit off of the bottom of the door to install sweeps that go under the door. Sweeps on the outside of the door have the same problem as door stops, in that they tend to get clogged with snow.
The best weatherstripping for the bottom of the door is what is called an Automatic Door Bottom, or I like to call it the GUILLOTINE. These have a plunger on the hinge side of the door that hits a strike plate on the door frame when you close the door. The plunger pushes the weatherstripping down into firm contact with the sill. This gives good weatherstripping without dragging the seal all across the floor. They seal better and last longer than all other bottom seals. Occasionally you will find surface mounted types for sale in hardware stores but at KNCrowder.com you can obtain the quality ones shown above either through their distribution system or directly from their web site.
Remember that in the summer time, if the sun hits a storm or screen door that is placed over a main entrance door, especially if the main door is insulated, the temperature between the two doors can get high enough to melt the plastic, peel the paint and generally wrack havoc. Hence in the summer time we do not want effective weather-stripping on a storm or screen door, we want the air to circulate and cool it down.