I am installing a couple outlet outside and I noticed a significant price difference between a standard GFCI outlet and the WR GFCI ones.
If I put a GFCI outlet in a weather resistant box why would I need a WR one?
First the NEC defines any receptacle, device or light fixture installed outdoors as a wet or damp location no matter what type of enclosure it is in.
NEC Article 406.4 (D)(6) states that any receptacle installed in a damp or wet location must be labeled suitable for that location (WR).
The difference between a WR and a non WR receptacle is that the WR has additional corrosion protection. Which makes sense even if you install a receptacle in an approved cover, it is still subject to condensation and corrosion.
Hope this helps and stay safe.
Weatherproof boxes aren't. Weather resistant GFCIs aren't.
My dad taught me a rule about not leaving valuable electronics out in the weather. I wouldn't put a GFCI anywhere I wouldn't put a smartphone.
Every GFCI device, even the GFCI+receptacle variety, has a feature that lets it protect downline parts of a circuit. Put such a device upline of the outdoor receptacle, and you've provided GFCI protection to the receptacles.
Now you use a plain WR receptacle and a sticker that says "GFCI Protected".