Why is the ninth month called September?
Old English suð "southward, to the south, southern, in the south," from Proto-Germanic *sunthaz, perhaps literally "sun-side" (cf. Old Saxon, Old Frisian suth "southward, in the south," Middle Dutch suut, Dutch zuid, German Süden), and related to base of *sunnon "sun" (see sun (v.)). Old French sur, sud (French sud), Spanish sur, sud are loan-words from Germanic, perhaps from Old Norse suðr.
As an adjective from c.1300; as a noun, "one of the four cardinal points," also "southern region of a country," both late 13c. The Southern states of the U.S. have been collectively called The South since 1779 (in early use this often referred only to Georgia and South Carolina). South country in Britain means the part below the Tweed, in England the part below the Wash, and in Scotland the part below the Forth. South Sea meant "the Mediterranean" (late 14c.) and "the English Channel" (early 15c.) before it came to mean (in plural) "the South Pacific Ocean" (1520s). The nautical coat called a sou'wester (1836) protects the wearer against severe weather, such as a gale out of the southwest.
Heb. Negeb, that arid district to the south of Palestine through which lay the caravan route from Central Palestine to Egypt (Gen. 12:9; 13:1, 3; 46:1-6). "The Negeb comprised a considerable but irregularly-shaped tract of country, its main portion stretching from the mountains and lowlands of Judah in the north to the mountains of Azazemeh in the south, and from the Dead Sea and southern Ghoron the east to the Mediterranean on the west." In Ezek. 20:46 (21:1 in Heb.) three different Hebrew words are all rendered "south." (1) "Set thy face toward the south" (Teman, the region on the right, 1 Sam. 33:24); (2) "Drop thy word toward the south" (Negeb, the region of dryness, Josh. 15:4); (3) "Prophesy against the forest of the south field" (Darom, the region of brightness, Deut. 33:23). In Job 37:9 the word "south" is literally "chamber," used here in the sense of treasury (comp. 38:22; Ps. 135:7). This verse is rendered in the Revised Version "out of the chamber of the south."