Will skies be clear over southern Ontario Monday night?
Partly clear skies are likely over regions near and north of Lake Ontario during the evening, except for lots of low-level moisture (illustrated below for mid-evening) that is likely to be visible as occasional cloudiness. Over southwestern regions, cloudy skies are expected due to substantial mid-level moisture (illustrated below for mid-evening) moving eastward over southern Ontario that will cause skies near Lake Ontario to become cloudy later in the evening or after midnight.

Will skies be clear over southern Ontario Sunday night?
Skies may occasionally become partly or mostly clear over some regions of southern Ontario near and east of the GTA overnight as moisture and vertical uplift gradually decrease by sunset. Over southwestern Ontario, mostly cloudy skies are expected due to more moisture in the atmosphere. The forecast charts below show mid-level and low-level moisture decreasing near Lake Ontario and more substantial moisture over southwestern Ontario during the evening.

Will skies be clear over southern Ontario Sunday night?
Mostly clear skies are likely except for low-level cloudiness during the early evening over some regions near and north of GTA, due to low-level moisture east of Lake Huron (illustrated below for early evening) and except for some jetstream-level cloud that may occasionally appear over some regions, due to jetstream winds forecast to be over southern Ontario (illustrated below for Sunday evening).

Will skies be clear over southern Ontario Saturday night?
Mostly clear skies are expected, except for evening high clouds over southwestern regions caused by some jetstream-level moisture which is forecast to move southeastward from southwestern Ontario during the evening (illustrated below for early evening) and then some low-level clouds are likely to spread across most regions, mainly after midnight, caused by low-level moisture which is forecast to flow southeastward over regions south and east of Lake Huron and Georgian Bay (illustrated below for early Sunday morning).

Will skies be clear over southern Ontario Friday night?

Lots of high, mid and low-level moisture along with some regions of uplift will be present to cause cloudiness, and the jetstream will be over southern Ontario overnight to contribute some high clouds, but some clear periods are likely over many regions. The charts below show mid-level moisture over most of southern Ontario during the evening.

Will skies be clear over southern Ontario Thursday night?
Partly clear skies are expected with lots of low-level cloudiness possible during the evening and less cloudiness likely by late evening.

Will skies be clear over southern Ontario Sunday night?
Clear skies are expected during early evening, followed by increasing high clouds later in the evening and then widespread cloudiness before morning, except for lots of low-level cloudiness during the evening over some regions south and east of Lake Huron and Georgian Bay. Illustrations below show the forecast charts for low-level moisture during early evening and high-level moisture during late evening.

Willl skies be clear over southern Ontario Saturday night?
Mostly cloudy skies are likely, mainly due to lots of low-level moisture especially south and east of Lake Huron and Georgian Bay, but occasional clear breaks are likely to appear over many regions. Then, some clearing is likely before dawn especially over southwestern regions following the passage of a low pressure trough across central and southern Ontario overnight.

Will skies be clear over southern Ontario Friday night?

Mostly clear skies are likely over most regions overnight after low-level cloudiness dissipates during twilight, except for lots of low-level cloudiness over regions south and east of Lake Huron and Georgian Bay.

Will skies be clear over southern Ontario Thursday night?

Mostly clear skies are likely over most regions after some low-level clouds dissipate following sunset, except for more persistent cloudiness due to low-level moisture south and east of Lake Huron and Georgian Bay (illustrated below for early evening).

Will skies be clear over southern Ontario Wednesday night?
Mostly cloudy skies are expected, followed by partially clearing skies before Thursday morning, as moisture and cloud associated with a low pressure trough (over Quebec and northeastern Ontario) gradually move eastward from southern Ontario overnight.