When Is Summer Starting In Canada 2025. Thursday, june 20 is the official first day of northern astronomical summer for 2025 — summer solstice — which is the longest day of the year for this half of the planet. Fall begins with the autumnal equinox, sunday, september 22, 2025, 8:44 a.m.

Winter begins with the winter solstice, saturday, december 21, 2025, 4:21 a.m. Canada 2025 calendar online and printable for year 2025 with holidays, observances and full moons