Busiest month of year for northern states campgrounds?

Late June, July and August!

Was in Munising MI (U.P.) a couple years ago in mid July and it was cold! topped out at mid 50`s for the week. the day we left it hit 63. the next week it was in the 80`s. told my wife that trip didn't count and we had to do it over but the last week of July or August. LOL

At one campground in Northern MI, last week, we reserved one of the last spots available in middle august.

August in the UP Wisconsin wasn't too bad last year. We didn't make advanced reservations anywhere and Labor Day Weekend was the only time we had to "settle" for our 2nd pick.

drsteve wrote:
Depends how far north we're talking... Northern MI in early June is a great place for a snowstorm.

Agreed on that. Did the UP first week in June a while back and it bordered on Cold some days. One of the best times I have had camping. We virtually had the entire place to ourselves and all the waterfalls were raging.

Depends how far north we're talking... Northern MI in early June is a great place for a snowstorm.

July/August in New England and holiday weekends in May, September and October.

I guess it depends on what you mean by northern.
In the Lake States, June is a prime time for black flies and mosquitoes, which can sometimes mean a less than pleasant camping experience.

Later July and into August are probably more likely the prime times for camping. While some states begin school in early to mid-August, Minnesota usually starts near the last day of August, so almost all of August is available for vacation and/or camping.

July/August in WI. Many school systems here are open until nearly mid-June.

July because some of the kids return to school in August.

I think it is July - because you are including the 4th of July.