Point Pelee National Park is the warbler capital of Canada. The second week of May is the time to go. The park opens at 5 a.m. for birders during the migration.
Here is a list of the warblers that you have a good chance of seeing at Point Pelee in May, (C) denotes the most common ones.
Blue-winged Warbler
Golden-winged Warbler
Tennessee Warbler (C)
Orange-crowned Warbler
Nashville Warbler (C)
Yellow Warbler (C)
Chestnut-sided Warbler (C)
Magnolia Warbler (C)
Cape May Warbler (C)
Black-throated Blue Warbler (C)
Yellow-rumped Warbler (C)
Black-throated Green Warbler (C)
Blackburnian Warbler (C)
Pine Warbler
Palm Warbler (C)
Bay-breasted Warbler (C)
Blackpoll Warbler
Cerulean Warbler
Black-and-white Warbler (C)
American Redstart (C)
Ovenbird (C)
Northern Waterthrush
Mourning Warbler
Common Yellowthroat (C)
Wilson’s Warbler (C)
Canada Warbler (C)
Of course, there are plenty of other birds besides Warblers.