Ugaritic

yr - early rain (DUL 977)

PC
*yāriy- - early rain (Kogan 2015: 315)
The origin of PC *yāriy- is uncertain, but it is tempting to surmise (with DRS 621‒622) a connection with the widely attested verbal root *rwy ‘to be saturated with water’ (for which v. HALOT 1194‒1195 and CDG 478).