The cloud inversion app for UK mountains
Standing above a sea of cloud takes the right morning and the right hill. Peakify forecasts both. The iPhone app ranks mountains by their chance of a cloud inversion over the next 7 days, explains each score, and can send you an alert when one of your favourite hills looks likely.
Download Peakify on the App StoreToday's best cloud inversion chances
The UK summits with the highest cloud inversion scores for today, from the same forecast the app uses:
- Ben Macdui North Top Cairngorms · 1,294 m 94% · Excellent
- Ben Macdui Cairngorms · 1,309 m 93% · Excellent
- Stob Coire Sputan Dearg Cairngorms · 1,251 m 92% · Excellent
- Cairn Lochan Cairngorms · 1,214 m 91% · Excellent
- Carn na Criche Cairngorms · 1,265 m 91% · Excellent
See the full table of up to 40 peaks on the UK cloud inversion forecast.
What the cloud inversion app does
7-day inversion forecast
Mountains ranked by their chance of a cloud inversion over the next 7 days, as a list or a map, with country and score filters and the reasons behind each score.
Cloud inversion alerts
Turn on alerts and Peakify sends a notification when one of your favourite mountains scores 70% or more, naming the day.
The best hour
Open a mountain for the best hour between three hours before sunrise and two hours after, how long the inversion should last, and a confidence rating.
In the Mountain Briefing
When an inversion is likely, the summit forecast tells you the top may be above the cloud and links to the full inversion forecast.
Inversion widget (Pro)
A Home Screen widget can show inversion details for a favourite mountain, alongside its weather, wind and visibility.
Sunrise planning
The Sun and Moon planner shows where the sun will clear the skyline from your spot, using real terrain, so you know when the light will hit the cloud.
How Peakify forecasts a cloud inversion
For each mountain, Peakify finds the lowest ground within 6 km of the summit, where fog would pool, and pulls an hourly forecast for both the summit and that valley. It looks for a stable, layered atmosphere, valley air close to saturation, dry air above the summit, overnight cooling and a long night. Then it checks the things that spoil an inversion: wind at summit height, overnight cloud, air pressure, wind in the valley and fog that is deeper than the hill is high. The result is a percentage: 70% and over is Excellent, 50 to 69% Good and 30 to 49% Possible.
New to them? Read what a cloud inversion is and when they form. They are most common on calm, clear autumn and winter mornings under high pressure, often after a damp day.
Cloud inversion app questions
Is there an app that forecasts cloud inversions?
Yes. Peakify is a free iPhone app that ranks mountains by their chance of a cloud inversion over the next 7 days and explains each score. The same cloud inversion forecast is on peakify.ai/cloud-inversions.
How do cloud inversion alerts work in the app?
Save the hills you climb as favourites and turn on cloud inversion alerts. When one of them scores 70% or more, Peakify sends a notification naming the mountain, the chance and the day.
What time should I be on top for a cloud inversion?
Before sunrise. Peakify scores each hour from three hours before sunrise to two hours after and gives you the best one, along with the sunrise time. The fog usually thins once the sun warms the valleys.
How accurate is the cloud inversion forecast?
Treat it as a guide and check again the evening before. Each mountain shows a confidence rating, High when the ECMWF and Met Office models agree on a calm, clear valley at dawn and Low when they disagree.
More in the app: every Peakify feature, from summit forecasts to GPS navigation and emergency SOS.