Compare the mountain weather on Yr Wyddfa, Cadair Idris and Pen y Fan before choosing a day for the Welsh Three Peaks.
Every summit is shown side by side. The combined grade gives extra weight to the weakest forecast.
A wild day on the tops of Snowdon - Yr Wyddfa, with very strong, gusty winds and burns likely to be in spate.
A poor day on the tops of Cadair Idris - Penygadair, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Pen y Fan, with very strong, gusty winds and sleet or snow up high.
Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.
Waxing gibbous moon
Moon up during darker hours18:45 BST to 01:45 BST next morning
Window: 20 Oct, 17:00 BST to 21 Oct, 08:00 BST
Waxing gibbous moon
Moon up during darker hours18:45 BST to 01:45 BST next morning
Window: 20 Oct, 17:00 BST to 21 Oct, 08:00 BST
Waxing gibbous moon
Moon up during darker hours18:45 BST to 01:45 BST next morning
Window: 20 Oct, 17:00 BST to 21 Oct, 08:00 BST
Waxing gibbous moon
Moon up during darker hours18:45 BST to 03:05 BST next morning
Window: 21 Oct, 17:00 BST to 22 Oct, 08:00 BST
Waxing gibbous moon
Moon up during darker hours18:45 BST to 03:05 BST next morning
Window: 21 Oct, 17:00 BST to 22 Oct, 08:00 BST
Waxing gibbous moon
Moon up during darker hours18:40 BST to 03:05 BST next morning
Window: 21 Oct, 17:00 BST to 22 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.
The Welsh Three Peaks Challenge links three iconic mountains across north, mid and south Wales. Because the summits are widely separated, the forecast can vary far more than a single Wales-wide weather summary suggests.
Treat the combined grade as a quick comparison, then read each mountain row. A good forecast on one summit does not imply similar wind, cloud or rain on the other two.
Read Welsh Three Peaks route information