Will skies be clear over southern Ontario Saturday night?
Most regions are likely to be cloudy by sunset. Partly clear skies are likely over eastern regions of southern Ontario during early evening, except for high thin cloudiness, and then cloudy skies are expected by late evening due to moisture spreading northeastward over southern Ontario ahead of a low pressure trough moving over the southern Great Lakes region.
The illustrations below show the extent of high-level and mid-level moisture during late evening.

Will skies be clear over southern Ontario Thursday night?

Clearing skies are expected, beginning by sunset in southwestern regions, and probably not clearing in the GTA until after midnight, due to moisture moving eastward from southern Ontario during the evening (illustrated below for late evening). Low-level clouds are likely to be visible overnight occasionally in many of the regions that become clear.

Will skies be clear over southern Ontario Wednesday night?

Partly clear skies are expected over most of southern Ontario but high cloudiness is likely to be visible over most of the regions where the low cloud eventually clears.

Will skies be clear over southern Ontario Tuesday night?

Skies are likely to be mostly clear over southwestern regions and cloudy elsewhere over most other regions of southern Ontario, due to mid-level moisture moving northeastward from southern Ontario overnight (illustrated below for late evening) and allowing skies to become mostly clear over southwestern regions.

Will skies be clear over southern Ontario Monday night?

Partly clear skies are expected, except for increasing high clouds, due to increasing jetstream-level moisture which is forecast to move northward over southern Ontario overnight (illustrated below for late evening). More substantial cloudiness is likely to move northward over southern Ontario during early morning.

Will skies be clear over southern Ontario Sunday night?
Partly cloudy skies are expected due to high-level moisture moving southward over Ontario and forecast to be over most of southern Ontario overnight (illustrated below for late evening). Southwestern regions are more likely to be mostly clear during early evening with thin high-level cloudiness increasing later in the night.

Will skies be clear over southern Ontario Saturday night?

Mostly clear skies are expected, except for diminishing high cloudiness at sunset and except for some mid-level cloudiness that might appear over northern regions, due to some mid-level moisture which is forecast to move over regions near and east of Georgian Bay (illustrated below for late evening).

Will skies be clear over southern Ontario Friday night?
Cloudy skies are expected during the evening, followed by partly clearing skies as the night progresses and moisture with a low pressure system moves eastward. Skies are more likely to become mostly clear before sunrise over southwestern regions and less likely over eastern regions.

Will skies be clear over southern Ontario Thursday night?
Partly clearing skies are likely over southwestern regions after midnight, due to mid-level moisture moving eastward from southern Ontario (illustrated below for EDT 02:00) but low-level moisture is likely to cause some low-level clouds and possible fog over regions that become partly clear.

Will skies be clear over southern Ontario Tuesday night?

Skies will appear to be mostly cloudy due to increasing and widespread high-level moisture over southern Ontario (illustrated below for late evening) but breaks in the high cloudiness early in the evening could allow the brighter stars and Jupiter to appear and give the impression of partly clear skies.

Will skies be clear over southern Ontario Monday night?
Mostly cloudy skies are likely during early evening over most regions until some mid-level moisture which is forecast to be over southern Ontario (illustrated below for shortly before sunset) moves southward and allows skies to gradually become more clear later in the evening.

Will skies be clear over southern Ontario Sunday night?
Clearing skies are expected during the evening, but many regions will be under partly cloudy skies during the evening due to low-level moisture (illustrated below for late evening) which is forecast to gradually move southeastward from southern Ontario overnight.

Will skies be clear over southern Ontario Saturday night?
Skies are likely to be mostly clear, except for scattered or occasional mid and low-level clouds that are likely to appear over most regions from time to time, due to some moisture over southern Ontario overnight (illustrated below for early Sunday).

Will skies be clear over southern Ontario Friday night?
Skies are likely to be mostly clear during the evening, except for some high clouds that will likely be increasing later in the evening. Southwestern regions are likely to become cloudy by late evening, due to mid-level moisture which is forecast to move eastward over southwestern Ontario (illustrated below for late evening). Other regions east of southwestern Ontario may not become cloudy until morning, except for the increasing high cloudiness.

Will skies be clear over southern Ontario Thursday night?
Partly clear skies are expected over eastern parts of southern Ontario due to some low-level clouds that may appear during the evening (caused by low level moisture, illustrated below for late evening) and mostly cloudy skies are expected over western regions during most of the night (caused by mid-level moisture over southwestern Ontario, illustrated below for late evening).

Skies are likely to become mostly clear by early evening, except for some regions where some low or mid-level clouds may appear, due to low and mid-level moisture remaining over southern Ontario after sunset (illustrated below for late evening). Then, increasing cloudiness (not illustrated) is expected before morning twilight.

Will skies be clear over southern Ontario Tuesday night?
Mostly cloudy skies are likely, due to low-level moisture as well as jetstream-level moisture forecast to be over southern Ontario (illustrated below for late evening) but some breaks in the low cloud cover over some regions from time to time may allow bright moonlight to give the appearance of partly clear skies.

Will skies be clear over southern Ontario Saturday night?
Mostly clear skies are expected, but some mid-level and high-level cloudiness is likely to appear over most regions from time to time, due to jetstream-level moisture over southern Ontario (illustrated below for the sunset hour) and due to mid-level moisture which is forecast to move across some regions of southern Ontario (illustrated below for late evening).

Will skies be clear over southern Ontario Friday night?

Mostly clear skies are expected, with a high pressure ridge and dry airmass moving over southern Ontario, except that some jetstream-level clouds could appear occasionally, due to the jetstream over southern Ontario overnight (illustrated below for late evening), as well as occasional low-level clouds that may appear from time to time until the moisture (moving eastward during Friday afternoon) is completely replaced by dry air.

Sunday April 2: no updates will be posted today but increasing cloudiness seems very likely for Sunday evening over southern Ontario.

Will skies be clear over southern Ontario Saturday night?
Skies are likely to be clearing by about sunset, and some low and mid-level clouds are likely to be visible from time to time overnight as a result of moisture which is forecast to be over southern Ontario (illustrated below for late evening).