Tom
There is no need to travel all the way to Hawk Cliff in the fall as there is a very good Raptor viewing area right in Toronto at High Park called Hawk Hill that is active from Sept. 1st to Nov. 30th every year.
The season starts with Ospreys, Sharp-shinned Hawks and A. Kestrels moving on to Cooper's and Broad-winged Hawks (sometimes in their thousands) then Bald Eagles to Merlins, Perigrine Falcons, Red-tailed and Rough-legged Hawks. In mid Oct. the Golden Eagles pass through and during most of Sept. and Oct. there are many hundreds of Turkey Vultures passing through. Also passing in good numbers are N. Goshawks, N. Harriers, and also to be watched for are the numerous Passerines that also migate through.
Some of the Passerines are Eastern Bluebirds, C. Loons, R-T Hummingbirds, thousands of BlueJays, Crows, Rd-winged Blackbirds and C. Grackles, Sparrows, Finches, Warblers and Grosbeaks. I personally have seen 136 species on and over Hawk Hill during this time and if a fallout occurs while you are at The Hill then you have a large park to fill your day with birds.
There are always bird identifiers on the hill and all are welcome.
DIRECTIONS TO HAWK HILL IN HIGH PARK
High Park is located in the west end of Toronto and is bounded on the south by The Queensway, the north by Bloor Street and on the east by Parkside Drive.
To reach High Park you can take the TTC Subway to the High Park Station or the Queen Street Streetcar #501 to either the Parkside Drive or the Colborne Lodge Drive streetcar stops or you may drive in from High Park Avenue at the north end of the park.
Hawk Hill is east of or right beside the Algonquin Restaurant (about halfway into the park) which is south of the soccer field. If you can not find the hill for the trees then you can enquire at the restaurant as to the location as almost everyone is aware of the goings on up there now.
There is always someone on the hill from Sep. 1st to around Nov. 30th.
Best days are days with a good NW or N wind and if a cold front comes along with those winds after a rainy day then you should see lots of Raptors (No Guarantees).