Note: no posts will be updated until Tuesday, September 19.
Clear skies!

Will skies be clear over southern Ontario Thursday night?

Mostly clear skies are expected over most regions, except for some low-level cloudiness in regions near the GTA during the evening, until low-level moisture (illustrated below for late evening) is forecast to diminish and allow skies to become clear. Fog is likely to form before morning in many regions and the high humidity will cause significant dew during the night.

Will skies be clear over southern Ontario Wednesday night?
Mostly cloudy skies are expected, due to moisture from the storm south of Ontario that was Hurricane Irma, but gaps in the moisture may allow occasional periods of partly clear skies over some regions (especially northern regions closer to Georgian Bay than Lake Erie) overnight that may be clear enough to allow aurora to be seen if the aurora becomes active.

Will skies be clear over southern Ontario Tuesday night?

Mostly cloudy skies are likely over southwestern regions, due to high-level clouds moving north ahead of post-tropical storm Irma, while mostly clear skies are likely further north over northern regions of southern Ontario (approximately north of Lake Ontario, depending on how far north the high clouds remain visible during the night).

Will skies be clear over southern Ontario Monday night?

Partly clear skies are expected, due to dry air associated with a strong high pressure ridge over Ontario, except for high-level clouds that will likely be spreading northward from Tropical Storm Irma and will probably be visible over southern regions during most of the night and over most other regions during at least part of the night.

Note, no more posts will be updated until Monday September 11 (due to vacation).

Will skies be clear over southern Ontario Friday night?
Mostly cloudy skies are expected over most southern regions, due to high-level cloudiness spreading northward over southern Ontario ahead of the remnant of Hurricane Harvey, illustrated below. The high cloudiness may occasionally be thin enough to allow the moon and brighter stars to give the impression of clear skies over some regions. Some northern regions are likely to remain mostly clear, depending on how far northward the high cloud can spread before getting dispersed in the high pressure ridge over northern Ontario.