The wet June and July in Windsor-Essex had now has some local vineyard owners worried.
"There's an old saying that grapes don't like wet feet," said Tom O'Brien, president of Essex-Pelee Island Coast Wine Growers.
He said the five weeks of hot, dry weather after the rain helped turn things around but grape crops are two or three weeks behind.
O'Brien said as grapes mature, sugar levels go up while acid levels falls.
The time to pick the grapes is when those levels cross each other.
"You want to have a white wine that is crisp and fruity, and we need acid and a little bit of sugar," O'Brien said. "With your red wines, you want it soft and full-bodied, so you want more alcohol and you want less acid."
Harvesting has started and should last until the end of October.
O'Brien said this should be a good year for grapes, as long as there's not a lot of rain this fall.
But, O'Brien admitted every year brings its challenges.
"In 2012, we had a real drought and we got an amazingly high sugar, good acid yield from the crop," he said. "In 2011, we had a lot of rain in the fall and a very large bumper crop. The grapes were good, but you had to get them off quickly.
"Mother Nature does funny things and our grapes and wine that we grow here are truly at her mercy."