Will skies be clear Monday evening over southern Ontario?

 It looks like the early sunset may allow several hours of mostly clear skies over many parts of southern Ontario before mid-level cloudiness increases ahead of a low pressure trough moving eastward over southern Ontario during Tuesday, especially over the regions north and west of Toronto. The bright full moon and resulting few stars visible may give the appearance of a mostly clear sky, even while cloudiness increases, but increasing moisture and cloudiness will probably be apparent during early evening over southwestern Ontario and later in the evening over regions east of Toronto.

Below: forecast chart showing mid-level (500 hPa-level) moisture at UTC 03:00 (EDT 22:00 Monday evening)