Why do the doors of my 97 Jetta "freeze" in the winter, when

Why do the doors of my 97 Jetta "freeze" in the winter, when it gets really cold ?
I can put the key, but frequently can not turn it.

And, on occasion, when I can turn the key to unlock all the doors, they're all frozen shut and I can not open any of the doors.

This doesn't happen on other cars ie with other people I know who live in the same environment/temperatures, so has anybody heard of a design flaw or recall on this ?

Spray WD 40 in the lock cylinders to take off and prevent extra moisture before winter you may also purchase lock de icer to squirt in the keyhole at parts stores or use a little rubbing alchohol to de ice them and lube the door seals to the car body with silicone grease parts stores to prevent sticking do not use silicone spray as it makes everything too slippery, you just want the door gaskets to be lubed. Common problem in Wisconsin winters if parking outside.

It happens on most smaller cars,the moisture,or water is frozen.I had to pour hot coffee on mine to open the door last winter,in Oklahoma.

I have had different size cars from a Chevy Lumina to the Toyota Corolla S that I drive now..and it generally happens to me unless I park my car under the carport. The dew settles at night and freezes which causes the doors to freeze shut. A simple hair dryer with an extension cord or a glass of cool water NOT HOT or it'll crack your window poured over the door frame does the trick every time.

its all about moisture. it prevents the tumblers in you lock from turning. it also freezes your rubber seals on your door to your car. I think you may be able to coat the seals with wiped on wd40 or something. you may also squirt this in your keyholes. this must be done above freezing and when everything is dry. it's preventative, most likely not something that will fix one already frozen.

I have a 94 VW Golf and it happens all the time in the winter. Not sure if it has anything to do with the vaacum locks or if the tumblers are just prone to freezing. I keep lock deicer in my pocket all winter . and typically need it two or three times.