Will skies be clear over southern Ontario Monday night?
Cloudless skies are expected, but smoke aloft (illustrated below) from western wildfires will definitely reduce transparency.

Will skies be clear over southern Ontario Sunday night?

It looks like skies will become partly or mostly clear over most regions as moisture gradually moves eastward from southern Ontario during Sunday afternoon and evening (illustrated below), except for partly cloudy skies that may develop over some regions.

Will skies be clear over southern Ontario Saturday night?

Mostly cloudy skies are likely, but gradual clearing is likely overnight and early Sunday as mid-level moisture gradually moves eastward from southern Ontario (illustrated  below) and allows the full moon to occasionally become visible over some regions.

Will skies be clear over southern Ontario Friday night?

Increasing high cloudiness, due to jetstream-level moisture that is forecast to move eastward across southern Ontario overnight (illustrated below) will cause skies to appear partly or mostly cloudy, except for some periods with less cloudiness when the appearance of the brighter stars and moon may give the impression of clear skies (especially from urban areas where the fainter stars are not visible). Smoke from western wildfires moving across southern Ontario during Friday may also reduce the clarity of the skies if some stars are visible.

  

Will skies be clear over southern Ontario Thursday night?

Skies are likely to become clear by sunset over most regions, except for some cloudiness during the evening near western Lake Ontario, caused by low-level moisture gradually moving eastward from southern Ontario (illustrated below) during the evening.

Will skies be clear over southern Ontario Wednesday night?

It looks like skies ought to be clearing during late evening over most regions as mid-level moisture (illustrated below) gradually moves eastward from southern Ontario. The GTHA area may not start to experience clearing skies until after midnight.

Skies will likely be mostly cloudy Tuesday night over southern Ontario, but there will be lots of locations where skies may become partly or mostly clear from time to time. A large upper level low over Ontario that is circulating regions of moisture (and dry regions) as well as patches of vertical rising motion (as well as sinking motion is other regions) makes it impractical to estimate where or when clear skies will develop.