Scottish weather forecasts are written in a dialect of English that takes years to learn. "Wintry showers" means it might rain, might snow, might do both. "Chance of cloud-free Munros: 30%" means don't bother with the summit. "Bright spells" means it'll rain for 45 minutes, the sun will come out for 10 minutes, and the Met Office will call it a win. Here's the translation guide.
The Three Forecasts, Ranked
1. MWIS (mwis.org.uk) — The Gold Standard
Mountain Weather Information Service. Written by humans who understand mountains. Updated twice daily. Covers specific mountain areas (West Highlands, Cairngorms, etc). The "chance of cloud-free Munros" line is the single most important piece of information for any Highland hiker. If it says 10%, choose a valley walk.
💡 Bookmark this. Check it the night before and again at 7am. It's more accurate than any app.
2. Met Office Mountain Forecast
Good for wind speeds and precipitation maps. The wind gust forecast is particularly useful — gusts over 30mph on summits mean you'll struggle to stand. Gusts over 50mph mean don't go. The hourly breakdown is more detailed than MWIS.
💡 Use for timing decisions: "The rain clears at 11am, can I wait?"
3. Your Phone's Weather App
Fine for "do I need a jacket in Inverness today?" Useless for mountain decisions. Phone apps don't account for orographic lift (mountains making their own weather) or the fact that conditions at 1,200m are completely different from conditions at sea level. Treat as entertainment, not information.
Key Phrases Decoded
- "Wintry showers" = could be rain, sleet, hail, or snow. Probably all four. Dress for everything.
- "Bright spells" = mostly cloudy with occasional brief sunshine. Don't forget waterproofs.
- "Breezy" = windy. "Windy" = very windy. "Gale force" = don't go up a mountain.
- "Cloud base 600m" = the mountain will be in cloud. If your summit is above 600m, you won't see anything.
- "Visibility poor in precipitation" = when it rains, you can't see. This sounds obvious but it's the most dangerous condition — you can navigate in cloud, you can walk in rain, but you can't do both without serious skill.
Editor's Note
I check MWIS obsessively — it's the first thing I look at in the morning and the last thing at night. It has saved me from at least three bad decisions, including one attempt on the Aonach Eagach ridge where the forecast said "winds easing" but MWIS said "gusts 45mph on ridges." MWIS was right. My nerves were grateful.