Will skies be clear over southern Ontario Wednesday night?
Mostly cloudy skies are likely during the evening, followed be gradually clearing skies as moisture gradually moves southward from Ontario overnight (illustrated below for late evening).

Will skies be clear over southern Ontario Tuesday night?

Mostly cloudy skies are expected, with lots of middle and high-level moisture forecast to be over southern Ontario (illustrated below for late evening) but breaks in the high cloudiness will occasionally allow the brighter stars and planets to appear and to give the appearance of partly clear skies. With the very humid air over southern Ontario, fog is likely to form in regions where skies become clear enough for the ground to radiate heat and cool down enough for fog to develop.

Will skies be clear over southern Ontario Sunday night?
Mostly clear skies are likely, except for some clouds that may be visible occasionally due to some moisture over southern Ontario (illustrated below for mid-level moisture during late evening) and except for widespread smoke from western forest fires spreading over most of North America (illustrated below for Saturday, August 4).

Will skies be clear over southern Ontario Saturday night?
Mostly clear skies are expected (following some cloudiness during early evening) except for some cloudiness that is likely to appear occasionally due to patches of mid-level and jetstream-level moisture which are forecast to move over southern Ontario overnight (illustrated below for late evening).

Will skies be clear over southern Ontario Friday night?
Partly or mostly clear skies are expected with some scattered low clouds that may appear over various regions, and partly cloudy skies during the evening may result from leftover clouds remaining from thunderstorm activity near regions where thunderstorms develop during the afternoon or evening.

Will skies be clear over southern Ontario Thursday night?

Mostly cloudy skies are likely, due to widespread high cloudiness caused by jetstream-level moisture over most regions with the jetstream, spreading northward over southern Ontario overnight (illustrated below for late evening).

Will skies be clear over southern Ontario Monday night?
Mostly cloudy skies are expected, due to lots of high cloud, although the high cloud cover may occasionally be thin enough to allow the brighter stars and planets to be clearly visible and give the impression of a mostly clear sky.