Rashi on Genesis 8:22/רש"י על בראשית ח׳:כ״ב

1עוד כל ימי הארץ וגו' לא ישבתו WHILE THE EARTH REMAINETH … SHALL NOT CEASE — Of these six seasons each consists of two months, as we have learned (Bava Metzia 106b): Half of Tishri, Marcheshvan and half of Kislev is seedtime; half of Kislev, Tebeth and half of Shebat is the cold-season.

2קור COLD-SEASON is more severe than חורף winter.

3חורף WINTER is the time of sowing barley and pulse which are quick (חריף) to ripen. It is half of Shebat, Adar and half of Nisan.

4קציר HARVEST — Half of Nisan, Eyar, and half of Sivan.

5קיץ SUMMER — Half of Sivan, Tammuz and half of Ab. This is the time of fig-gathering, the time when they lay them out to dry in the fields. and its name is קיץ “summer-fruittime”, as (2 Samuel 16:2) “And the bread and the summer-fruit (קיץ) for the young men to eat”.

6חום HEAT — This is the end of the hot season, half of Ab, Elul and half of Tishri, when the world is excessively hot, as we have learned in Treatise Yoma 29a: “The end of the summer is worse than the summer itself”.

7ויום ולילה לא ישבתו DAY AND NIGHT SHALL NOT CEASE — From this we may infer that they (day and night) ceased during the period of the Flood, for the planetary system did not function, so that there was no distinction between day and night (Genesis Rabbah 34:11).

8לא ישבתו SHALL NOT CEASE — None of these shall cease to take their natural course.