Will skies be clear over southern Ontario Saturday night?
It looks like partly clear skies are likely, since stars will be visible, but some high-level moisture will cause some high cloudiness to appear over some areas most of the time, as well as increasing mid-level cloudiness over southwestern regions after midnight.

Will skies be clear Friday night over southern Ontario?

It looks like mostly clear skies are likely, except for some high-level moisture that may appear as thin cirrus, mainly over southwestern regions west of Toronto.

Will skies be clear Thursday night over southern Ontario?

It looks like mostly clear skies, except for possible scattered mid-level clouds caused by a region of mid-level moisture moving southward over southern Ontario during Thursday, but subsidence ought to minimize upward motion that forms clouds. Result: mostly clear skies.

Will skies be clear over southern Ontario Sunday night?
It looks like clear skies will continue overnight, caused by a high pressure ridge over southern Ontario.

Will skies be clear Saturday night over southern Ontario?
It looks like mostly clear skies are likely, except for some mid and high-level moisture that could appear as cloud patches occasionally, especially after midnight. The charts below show the jetstream position overhead (and this will provide some lift for the high-level moisture along the jet) and mid-level moisture after midnight especially near Georgian Bay.

 

Will skies be clear over southern Ontario Thursday night?

It looks like clear skies are likely, except for some high-level moisture which could occasionally appear as visible thin high clouds.

Will skies be clear over southern Ontario Monday night?
Clear skies are expected under a high pressure ridge building over southern Ontario later Monday. Some mid or high-level cloudiness may be visible over some regions east of thunderstorms that are likely to develop during the afternoon, until the clouds formed by the thunderstorms dissipate.
A problem for telescopes and optical surfaces exposed to the night sky will be dew that will be developing in the very humid air and with calm winds under the high pressure ridge.

Will skies be clear Sunday evening over southern Ontario?
It looks like skies will be mostly clear except for high cloudiness that will be thickest over southwestern regions, and gradually increase further east during the night, ahead of a frontal zone moving eastward across the central Great Lakes region during Sunday afternoon.

Will skies be clear over souithern Ontario Saturday night?
It looks like mostly clear skies are likely after sunset, except for some high-level moisture that appears to be forecast to move southward across southern Ontario overnight and cause some mid-level cloudiness that may appear occasionally, especially when illuminated by the bright moonlight. Some low-level cloudiness may also be visible during early evening, but is likely to disappear by or shortly after sunset.

Will skies be clear Monday night over southern Ontario?
It looks like mostly clear skies are likely over most regions. Some high-level cirrus over southern Ontario during the afternoon is forecast to diminish by evening, and some mid-level cloudiness over some regions during Monday is likely to dissipate after sunset (as the lifting motions that sustain the clouds diminishes). Any remaining mid-level cloudiness is more likely to be generally north of or east of the Toronto area during the evening, as seen on the chart for mid-level moisture below.

Will skies be clear over southern Ontario sunday night?
It looks like partly to mostly clear skies will be the best description, mainly for regions west of Lake Ontario, as skies gradually become more clear following the eastward movement of a low pressure trough across southern Ontario during Sunday afternoon and evening.

Will skies be clear over southern Ontario Saturday night?
It looks like mostly clear skies during early evening, followed by increasing high cloudiness, with more cloudiness over southwestern regions and less east of the GTA.

Will skies be clear Friday night over southern Ontario?
Mostly clear is the best description, since the only significant cloudiness visible will be high-level cirrus cloudiness moving across southern Ontario. The bright moonlight ought to help to make the cirrus visible.