MARK Weather Awareness
Weather is the thing that decides most days in the hills. The forecast is a guide — the mountain is the reality.
Where to check, what matters at altitude, and how to read the sky.
The Fundamentals
Check the Right Forecasts
Check MWIS, the Met Office mountain forecast, and mountain-forecast.com before every trip. Mountain-forecast.com shows temperature and wind at different elevations — base, mid-mountain, and summit — so you know exactly what you’re walking into. Never rely on the nearest town’s forecast; valley weather tells you nothing about what’s happening 600m higher.
Wind Is the Real Danger
Above 600m, wind speed and wind chill dictate everything. A 20mph wind at 5°C can feel like –1°C — and at 40mph, like –3°C. Cold enough to push you into hypothermia if you’re wet or moving slowly, even on what looks like a mild day.
Learn to Read the Sky
- Building cumulus means showers.
- Thickening altostratus means a front is moving in.
- A halo around the sun or moon means high-level moisture — usually rain within 12–24 hours.
- Fast-moving clouds at altitude tell you the wind on the ridge will be worse than what you’re feeling lower down.
Trust the Hill
Check at least two forecast sources. Beyond 48 hours, treat forecasts as trends, not truth. And if the hill gives you different information than the forecast, trust the hill.
MX Summary: Check the mountain forecasts, respect wind at altitude, and read the sky. The forecast is a guide — the mountain is the reality. If the two disagree, the mountain wins.