Will skies be clear over southern Ontario Thursday night?

Mostly clear skies are likely over most regions, except for some low clouds during early evening and then increasing high cloud before morning, due to mid-level moisture which is forecast to spread eastward over southern Ontario overnight (illustrated below for early Friday).

Will skies be clear over southern Ontario Wednesday night?

Mostly cloudy skies are expected, caused by lots of moisture over southern Ontario with vertical uplift, but clear breaks are likely to appear over most regions occasionally.

Will skies be clear over southern Ontario Tuesday night?
Mostly or partly clear skies are likely over most regions, except for lots of low clouds (especially during the early evening) caused by low-level moisture over southern Ontario (illustrated below for early evening).

Will skies be clear over southern Ontario Sunday night?
Clear skies are expected during the evening, except for some low clouds that may appear during the early evening, due to lots of low-level moisture over southern Ontario (illustrated below for early evening), and then high cloud is likely to start to appear after midnight as high-level moisture (illustrated below for early Monday) moves eastward over southern Ontario (ahead of Monday's low pressure storm).

Will skies be clear over southern Ontario Monday night?
Mostly clear skies are likely during the evening, except for low clouds over regions south and east of Lake Huron and Georgian Bay, due to low-level moisture (illustrated below for early evening). Then, later in the night, high cloudiness is likely to spread eastward across southern Ontario, caused by high-level moisture (illustrated below for early Tuesday).

Will skies be clear over southern Ontario Sunday night?

Mostly or partly clear skies are likely over some regions, except for lots of low cloudiness over regions south of Lake Huron and Georgian Bay. Also, low clouds may appear occasionally over the regions that remain mostly clear, due to low-level moisture which is forecast to be over portions of southern Ontario (illustrated below in the 850 hPa moisture forecast chart). Cloudier conditions are likely east of approximately the Oshawa area, due to mid-level moisture (illustrated below in the 700 hPa moisture forecast chart) which is forecast to spread westward overnight in circulation around a strong low pressure storm near the Atlantic coast.

Will skies be clear over southern Ontario Friday night?

Skies are likely to be partly clear over many regions during the first several hours after sunset, and then increasing high cloudiness is likely to appear during early evening. The appearance of the moon and brighter stars may cause the impression of mostly clear skies, before thickening cloud later in the evening. The illustration below shows the forecast jetstream-level moisture that will be causing high cloudiness during early evening.

Will skies be clear over southern Ontario Sunday night during the lunar eclipse?
It looks like low cloud will be causing some cloudiness especially south and east of Lake Huron and Georgian Bay, due to low-level moisture (illustrated below for Sunday evening and after midnight).

Will skies be clear over southern Ontario Wednesday night?
Mostly clear skies are likely during the evening, except for low cloud over some regions south and east of Lake Huron and Georgian Bay, caused by low-level moisture (illustrated below for mid-evening) and then increasing high-level cloud is likely to appear before sunrise, caused by high-level moisture which is forecast to move eastward over southern Ontario (illustrated below for early morning).

Will skies be clear over southern Ontario Monday night?
Mostly cloudy skies are likely, except for southwestern regions near Lake Erie, where partly clear skies are likely for several hours following sunset, until cloudiness moves southward over all regions ahead of tonight's low pressure trough.

Will skies be clear over southern Ontario Sunday night?
Mostly clear skies are likely during the evening, except for low cloud near and west of Lake Ontario, until high cloud spreads southward over southern Ontario later in the night, due to jetstream-level moisture (illustrated below for mid-evening).

Note: no further updates until Sunday January 13.
Clear skies!

Will skies be clear over southern Ontario Saturday night?
Mostly cloudy skies are expected over most regions, due to widespread low-level moisture (illustrated below for early evening) except for southwestern regions where skies may be mostly clear during the evening until the low-level moisture moves over most of southern Ontario.

Will skies be clear over southern Ontario Friday night?
Mostly clear skies are expected, except for some high cloud that might be visible, caused by jetstream-level moisture which is forecast to be over most regions (illustrated below for mid-evening) and except for fog patches and low-level cloud increasing later in the evening over most regions. High relative humidity may decrease visibility and make it harder to see any high cloud that may be present, leaving the appearance of clear sky. High humidity and fog formation may be more likely to occur in regions with lots of snow on the ground, mild temperatures and calm winds.

Will skies be clear over southern Ontario Thursday night?

Clearing skies are expected by mid or late evening over most regions, except for some low clouds, and except for mostly cloudy skies remaining over regions near and north of Lake Ontario, due to lots of low-level moisture which is forecast to gradually move eastward from southern Ontario (illustrated below for mid-evening).

Will skies be clear over southern Ontario Wednesday night?
Cloudy skies are expected until a low pressure trough moves eastward from Ontario after midnight (illustrated below for early Thursday), and then skies are likely to become partly clear over most regions before morning.

Will skies be clear over southern Ontario Wednesday night?
Cloudy skies are expected until a low pressure trough moves eastward from Ontario after midnight, and then skies are likely to become partly clear over most regions before morning.

Will skies be clear over southern Ontario Tuesday night?

Partly cloudy skies are expected, due to moisture at low, mid and high levels, and skies could occasionally become mostly clear at some locations, especially during early evening and then again before morning. The illustrations below show a region of mid-level moisture which is forecast to move northeastward across the Great Lakes region and southern Ontario overnight.