The marginal reading is far more accurate and gives a better sense. The northwest wind in Palestine commonly brings rain, and this was probably in the thought of the writer.

The north wind driveth away rain - The margin has, "The north wind bringeth forth rain." It is said that the "north wind brings forth rain at Jerusalem, because it brings with it the vapours arising from the sea that lies north of it." The marginal is the true reading; and is supported by the Chaldee, Syriac, and Septuagint; but the Arabic reads south wind.
A backbiting tongue - A hidden tongue.

The north wind driveth away rain,.... So the geographer (w) says, the swift north wind drives away the moist clouds; which usually come from the opposite quarter, the south. The word used has the signification of conceiving, and begetting, and bringing forth; hence some (x) render it to a different sense, and so the Targum,
"the north wind bringeth forth rain;''
and in this sense Gersom interprets it, and says,
"the north wind produces rain in Jerusalem, because it brings there the vapours that ascend from the sea, which lies north unto it;''
and the philosopher (y) says, that in the northern parts of the world the south wind produces rain; and in the southern parts the north wind produces it, as in Judea. But in Job 37:22, fair, fine, golden, serene, "weather", is said to "come out of the north"; agreeably to which, the north wind is by Homer (z) called the producer of serene weather; and by Virgil (a) "clarus aquilo", i.e. what makes serene. The Arabic version reads it, "the south wind"; and that does bring rain, and, as that version has it, excites the clouds. But the first reading and sense of the words seem best (b), and agree with what follows:
so doth an angry countenance a backbiting tongue; drives it away, discourages and silences it. When a man puts on a stern countenance, a frowning and angry look, on such who bring him slanderous reports and idle tales of their neighbours, and reproach and backbite them, it checks them, and puts a stop to their practices; whereas listening to them, and especially with an air of pleasure, encourages them in them; were there not so many that take pleasure in hearing those talebearers and backbiters, were they more roughly dealt with, as the blustering north wind does with the rain, there would not be so much of this evil practised.
(w) Dionysii Perieg. v. 532. (x) "parturiet", Montanus; "gignit", Junius & Tremellius; "parturit", Schultens. (y) Aristot. Metaphysic. l. 2. (z) Iliad. 19. v. 358. Odyss. 5. v. 295. (a) Georgic. l. 1. prope finem. (b) "Ventorum frigidissimi quos a septentrione diximus spirare, et reliquos compescunt, et nubes abigunt", Plin. Nat. Hist. l. 2. c. 47.

Slanders would not be so readily spoken, if they were not readily heard. Sin, if it receives any check, becomes cowardly.

Better, "As the north wind bringeth forth (Psalm 90:2) or produces rain, so does a concealed or slandering tongue produce anger."

The next group of proverbs extends from Proverbs 25:23 to Proverbs 25:28.
23 Wind from the north produceth rain;
And a secret tongue a troubled countenance.
The north is called צפון, from צפן, to conceal, from the firmament darkening itself for a longer time, and more easily, like the old Persian apâkhtara, as (so it appears) the starless, and, like aquilo, the north wind, as bringing forward the black clouds. But properly the "fathers of rain" are, in Syria, the west and the south-west; and so little can צפון here mean the pure north wind, that Jerome, who knew from his own experience the changes of weather in Palestine, helps himself, after Symmachus (διαλύει βροχήν), with a quid pro quo out of the difficulty: ventus aquilo dissipat pluvias; the Jewish interpreters (Aben Ezra, Joseph Kimchi, and Meri) also thus explain, for they connect together תחולל, in the meaning תמנע, with the unintelligible חלילה (far be it!). But צפון may also, perhaps like ζόφος (Deutsch. Morgenl. Zeitsch. xxi. 600f.), standing not without connection therewith, denote the northwest; and probably the proverb emphasized the northern direction of the compass, because, according to the intention of the similitude, he seeks to designate such rain as is associated with raw, icy-cold weather, as the north wind (Proverbs 27:16, lxx, Sir. 43:20) brings along with it. The names of the winds are gen. fem., e.g., Isaiah 43:6. תּחולל (Aquila, ὠδίνει; cf. Proverbs 8:24, ὠδινήθην) has in Codd., e.g., the Jaman., the tone on the penult., and with Tsere Metheg (Thorath Emeth, p. 21) serving as העמדה. So also the Arab. nataj is used of the wind, as helping the birth of the rain-clouds. Manifestly פנים נזעמים, countenances manifesting extreme displeasure (vid., the Kal זעם, Proverbs 24:24), are compared to rain. With justice Hitzig renders פנים, as e.g., John 2:6, in the plur. sense; because, for the influence which the tongue slandering in secret (Psalm 101:5) has on the slandered, the "sorrowful countenance" would not be so characteristic as for the influence which it exercises on the mutual relationships of men: the secret babbler, the confidential communication throwing suspicion, now on this one and now on that one, behind their backs, excites men against one another, so that one shows to another a countenance in which deep displeasure and suspicion express themselves.