I spent the weekend up on Pine Lake, just north of Vermillion and on my way back, I noticed that my Orange MN 2018 Registration stickers were peeling off in the wind!

I've had them on the canoe for about a year and had no issue. The only thing I can think of is that the 70 mph wind got to them after two days of rain/humidity?

Has this happened to anyone else who's stickers expire 2018? Any ideas on how to replace them?

I heard of this happening a few years ago. I'm not sure if the adhesive was bad on some rolls or not. I know you can get replacements from the License Bureau for a cost but you could explain what happened. I always remove the old sticker and clean the surface well because I'm afraid of this happening when going over an old sticker.
I hope you can get a replacement for free.

Yep have also had orange '18 stickers start to peel off a canoe and a pwc this summer. I used clear wide packing tape to overcoat them. Must be bad adhesive as you say.

Looks like duplicate decals are $6, from what I see here (Free + $6 issuing fee):

http://dnr.state.mn.us/licenses/watercraft/index.html

Never happened to me until the new ones this year. Since this is obviously a NEW problem with the registration stickers, I think they should replace them for free?

I'll confirm. They are 6. Just bought some replacements.

Yes, I got stickers last summer and one started coming off this year after driving through a hard rain. I emailed the DNR info line with my registration and info, and they just sent me new ones in a couple days. I think they are having a production problem in the last year or so. My opinion, people should not be responsible for stickers that won't stay on a boat under normal conditions.

Just put new stickers on this spring, already peeling. That's government adhesive for you.