Montenegro packs alps and Adriatic into a few hours' drive, so the best time to come depends on what you're chasing. High summer (July and August) is beach season: hot days, warm sea and lively coastal towns — but also the busiest and priciest, so book accommodation and Bay of Kotor boat trips well ahead.
Spring and autumn: the shoulder seasons
The shoulder months are the connoisseur's choice. May and June bring wildflowers, full rivers and green mountains with comfortable walking weather; September and early October keep the sea warm enough to swim while the crowds fade and the light turns golden. These are the sweet spots for combining coast and mountains in one trip.
Winter: skiing and a quiet coast
Winter is quieter but far from closed: Žabljak and Kolašin become Montenegro's ski resorts, the coast stays mild if subdued, and pilgrimage and heritage sites like Ostrog and Cetinje welcome visitors year-round. Two timing notes for the active: Tara Canyon rafting is at its wildest during the late-spring snowmelt, and the olive harvest colours the southern groves through autumn.