5th gear grind

[Mach83]

hey everyone. Wondering if anyone else came across this. I live in Albany,NY so it's getting a little colder up here now a days. I'm starting to notice that in colder weather 5th gear will grind when i shift? I have the same driving habits as i did the beginning of June. I'm pretty good at driving standard and since having the car for a year and a half i'm noticing that only 5th gear will grind when i put it in? anyone else come across this? thanks for the info