Last Day Of Summer 2024 Canada Calendar. The official last day of summer for 2024 is september 22, which is also the autumnal equinox. Learn how long summer lasts, why it ends on this date, and how it varies every year.

Here are the equinox and solstice dates—plus, answers to common questions about the. Thursday, june 20 is the official first day of northern astronomical summer for 2024 — summer solstice — which is the longest day of the year for this half of the planet.