Sion, Switzerland

If you're planning a trip built around landscapes and trails, Sion deserves a close look. This Switzerland destination lies at altitude, and its climate record peaks at a 93/100 sun score in July — 27°C afternoons under 53% average cloud cover.

The year runs from average lows of -1°C in January to highs of 27°C in July. On the rain ledger, December is the safest bet at a 39% chance of a wet day, while May climbs to 61%. Beach-warm afternoons (24°C and up) hold through June–August.

Averaged by season, sun scores land at 65 for spring, 92 for summer, 69 for autumn and 48 for winter — with typical afternoons of 16°, 27°, 17° and 8°C respectively. That makes summer the statistical sweet spot (season score 92), with autumn a workable second; winter is where the odds thin out. If your dates are flexible, August buys you 27°C warmth at the quiet end of the season.

Best months to visit Sion

Our month-by-month scoring puts July first (93/100), with June (92) and August (91) close behind. The dependable window is wider than the podium, though: May–October all score 70 or better. Skip December if sunshine is the point — it bottoms out at 47/100.

For context: in July, Sion is drier than 41% of the mountain destinations we track.

Month-by-month breakdown for Sion → · More destinations for July →

The live forecast backs this up: of the next 16 days, 6 look mostly clear and none carry meaningful rain risk, in a 2–18°C band. Today's cached sun score is 61/100.