A good day on Cairn Gorm, though expect cloud coming down onto the tops.
Cairngorms 4000s weather forecast
Compare Cairn Gorm, Ben Macdui, Cairn Toul, Sgòr an Lochain Uaine and Braeriach in one forecast view.
Forecast comparison
Every summit is shown side by side. The combined grade gives extra weight to the weakest forecast.
A mixed day on Ben Macdui, with a blustery wind and cloud coming down onto the tops.
A good day on Cairn Toul, though expect cloud coming down onto the tops.
A good day on Sgòr an Lochain Uaine, though expect cloud coming down onto the tops.
A good day on Braeriach, though expect cloud coming down onto the tops.
Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.
Moon for your challenge
Night before your chosen day: Sunday 18 October 2026
Cairngorms
Area reference: Ben Macdui. Local mountain horizons will vary.
Moon information is unavailable for this night at this summit. An earlier night may no longer be in the current forecast.
Night beginning Monday 19 October 2026
Cairngorms
Area reference: Ben Macdui. Local mountain horizons will vary.
Waxing gibbous moon
- Illuminated disc
- 63%
- Moonrise
- Outside this window
- Moonset
- 00:06 next morning BST
Moon up during darker hours18:40 BST to 00:05 BST next morning
Window: 19 Oct, 17:00 BST to 20 Oct, 08:00 BST
Approximate times in UK local time, for an open horizon. Moon-up periods are rounded to five minutes. Hills and cloud can hide the Moon. Illumination is the sunlit percentage of its disc, not how bright your route will be. Darker hours here begin after civil twilight. This almanac covers only the stated overnight window and does not change the weather grade. Take a headtorch and spare power regardless.
Planning the Cairngorms 4000s
The Cairngorms 4000s links five of Britain’s highest summits across a remote, exposed plateau and the Lairig Ghru. Even when the general pattern is settled, cloud, wind and temperature can differ across this large mountain area.
Use the challenge grade to compare dates, then inspect all five rows. The forecast does not account for river crossings, snow cover, navigation or the very substantial distance between summits.
Read Cairngorms 4000s route context