Compare all 15 summits over 3,000 feet in Eryri before committing to this long and serious mountain challenge.
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 wild day on the tops of Crib y Ddysgl, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Crib Goch, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Elidir Fawr, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Y Garn, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Glyder Fawr, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Glyder Fach, with very strong, gusty winds and burns likely to be in spate.
A wild day on the tops of Tryfan, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Pen yr Ole Wen, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Carnedd Dafydd, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Carnedd Llewelyn, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Yr Elen, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Foel Grach, with a real risk of thunderstorms and burns in severe spate.
Serious conditions on Garnedd Uchaf, with a real risk of thunderstorms and burns in severe spate.
A wild day on the tops of Foel-fras, with a real risk of thunderstorms and burns in severe spate.
Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.
Area reference: Glyder Fawr. Local mountain horizons will vary.
Waxing gibbous moon
Moon up during darker hours18:40 BST to 04:20 BST next morning
Window: 22 Oct, 17:00 BST to 23 Oct, 08:00 BST
Area reference: Glyder Fawr. Local mountain horizons will vary.
Waxing gibbous moon
Moon up during darker hours18:40 BST to 05:45 BST next morning
Window: 23 Oct, 17:00 BST to 24 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 3000s crosses the Yr Wyddfa, Glyderau and Carneddau ranges, taking in 15 summits above 3,000 feet. Its length, exposed scrambling and repeated high ground make a single valley forecast inadequate for choosing a day.
The combined grade is deliberately conservative and gives extra weight to the weakest summit. Review every row, especially Crib Goch and Tryfan, and use the full peak pages for timing and hazard detail.
Read BMC Welsh 3000s guide