Will skies be clear over southern Ontario Monday night?
Clear skies are expected, except for increasing high-level clouds during early morning, due to jetstream-level moisture which is forecast to move over southern Ontario (illustrated below for early Tuesday).

Sunday: clear skies are expected Sunday night over southern Ontrario.

Will skies be clear over southern Ontario Saturday night?
Mostly clear skies are expected over southwestern regions, and cloudy skies are expected elsewhere over southern Ontario.

Will skies be clear over southern Ontario Thursday night?

Mostly clear skies are expected during the evening, and then increasing high cloudiness is expected after midnight due to increasing jetstream-level moisture which is forecast to move northeastward over southern Ontario (illustrated below for early Friday morning) ahead of Friday’s low pressure trough.

Clear skies are expected over southwestern regions and cloudy skies are expected over the rest of southern Ontario, due to deep moisture (illustrated below) circulating around a low pressure region which is gradually moving eastward from eastern Ontario.

Will skies be clear over southern Ontario Monday night?

Mostly cloudy skies are expected, due to increasing high cloudiness ahead of Tuesday’s low pressure trough, although skies may remain clear enough during early evening over many regions for the waxing moon and brighter stars to be visible and give the impression of clear skies.

Note: no updates will be posted until Sunday April 22.
Clear skies!

Will skies be clear over southern Ontario Wednesday night?

Cloudy skies are expected, except for regions north and east of the GTA, where skies are likely to be partly clear for several hours during early evening with some low-level clouds, until increasing moisture at mid and high levels moves eastward over these regions by late evening (illustrated below for late evening).

Will skies be clear over southern Ontario Tuesday night?

Mostly cloudy skies are likely, except for partly clearing skies in southwestern regions later in the evening and overnight as extensive mid-level moisture (illustrated below for late evening) gradually decreases and gaps develop in the cloud cover.

Will skies be clear over southern Ontario Thursday night?
Cloudy skies are expected, except for brief partly clear skies that may develop over some regions following passage of a cold front by about sunset, but increasing high cloudiness ahead of an approaching frontal zone during the evening is expected to cause skies to be mostly cloudy.

Will skies be clear over southern Ontario Wednesday night?
Mostly clear skies are expected during evening, following some diminishing low-level cloud after sunset, and then increasing cloudiness is expected by about midnight in southwestern regions and after midnight in most other regions. The illustrations below show low-level moisture during early evening (around sunset) that will likely cause some low-level cloudiness, and then again early Thursday (after midnight Wednesday night).

Will skies be clear over southern Ontario Tuesday night?
Mostly cloudy skies are likely over most regions, except for mostly clear skies over regions near GTHA and western Lake Ontario during the early evening, until high clouds appear and increase later in the evening, caused by high-level moisture which is forecast to spread eastward across southern Ontario overnight (illustrated below for late evening).

Will skies be clear over southern Ontario Sunday night?
Increasing high cloudiness (caused by increasing jetstream-level moisture, illustrated below for late evening) is expected to cause cloudy skies over southwestern regions by sunset, while regions near and east of the western Lake Ontario and southern Georgian Bay are likely to be under mostly clear skies during early evening until the high cloudiness increases by late evening.

Will skies be clear over southern Ontario Saturday night?
Mostly clear skies are expected by late evening, after cloudiness caused by extensive low-level moisture moves eastward from southern Ontario (illustrated below for early evening).

Will skies be clear over southern Ontario Friday night?
Mostly cloudy skies are expected during the evening, followed by clearing skies, as mid-level and low-level moisture move eastward from southern Ontario by about midnight (illustrated below for late evening). Some regions south and east of Georgian Bay and Lake Huron are likely to be cloudy during most of the night.

Will skies be clear over southern Ontario Thursday night?
Mostly cloudy skies are expected, except for mostly or partly clear skies during early evening near and north of western Lake Ontario and the GTA until mid-level moisture moves over these regions later in the evening (illustrated below for early evening close to sunset).

Will skies be clear over southern Ontario Sunday night?
Mostly cloudy skies are expected during the evening, due to widespread high cloudiness caused by jetstream-level moisture which is forecast to move across southern Ontario (illustrated below for late evening) as well as lots of low clouds caused by low-level moisture which is forecast to be over most regions during the evening (illustrated below for late evening) and then clearing skies are expected between midnight and early morning.