Argyll and Loch Lomond mountain weather forecast.

The Arrochar Alps, Crianlarich and Argyll hills. Height-aware guidance for wind, cloud, rain and temperature.

Mountain Weather brief

Argyll and Loch Lomond

Wednesday 21 October 2026 · The Arrochar Alps, Crianlarich and Argyll hills

Confidence: Unavailable Why?

A comparable model-confidence estimate is not available for this forecast.

What matters most

A mixed day in Argyll and Loch Lomond, with a blustery wind.

High-ground wind · 900 m25-35 mph southeasterly Gusts · 900 m35-45 mph Cloud base1200-1500 m Feels like · 900 m-6 to -2°C
Regional median

Sunshine and sky

Cloud becoming more extensive. Cloud cover is likely to increase as sunshine becomes less frequent.

Modelled sunshine8.9 h89% of daylight
Early1 h sunshine
Midday4 h sunshine
Later1.9 h sunshine

These are direct modelled sunshine hours during daylight, not the probability of sunshine. Cloud cover and summit cloud are assessed separately in the forecast above. The regional median prevents one unusually bright or dull summit cell defining the whole area.

Overnight forecast: 17:00–08:00 (UK local time), in Wild camping below.

Morning · 08:00–12:00MixedSummit winds around 25-35 mph. Gusts around 40-50 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Summit cloud is more persistent early in this period, with better prospects later. Rain is forecast on some hills during this period.
52
Afternoon · 12:00–17:00GoodSummit winds around 20-30 mph. Gusts around 30-40 mph are possible on exposed ground. Rain is forecast on some hills during this period. Summit cloud is more likely to break later.
75

Conservative regional grades across representative summits, so one sheltered hill does not overstate the wider area.

01

High-ground wind (900 m)

At around 900 m, expect a south-easterly wind of 25–35 mph, gusting 35–45 mph. Gusts like that are strong enough to make walking into it hard work, with buffeting on ridges and edges.

02

Walking impact

Gusts of 35–45 mph are strong enough to make walking into it hard work, with buffeting on ridges and edges.

03

Rain and showers

Drizzle sets in during the early afternoon.

04

Cloud-free summits

Clear-summit estimate: about 35% early, about 70% around midday and about 55% later.

05

Cloud and visibility

The tops should stay mostly clear of cloud. The cloud base could be as low as 900–1200 m early in the morning. Good spells of sunshine are likely.

06

Temperature and wind chill

At around 900 m it will be 2 to 6°C, feeling like -6 to -2°C in the wind. It turns milder through the day. Take a hat, gloves, a windproof and a spare warm layer. Pack waterproofs too, and keep a warm layer dry in your pack.

07

Freezing level

The freezing level is above the summits.

08

Daylight

Sunrise 08:03, Sunset 18:03, about 10.0 hours daylight.

Overnight · 17:00–08:00Wild campingBetaAcross these hills, a mixed night to camp, mainly because of the wind: gusts of about 30 mph. 58Mixed · 600 m View detailsHide details
Regional night beginning Wednesday 21 October 2026

Full regional overnight outlook

Across these hills, a mixed night to camp, mainly because of the wind. Gusts reach about 30 mph on open ground, so peg out well and use the guylines. Look for shelter from the southeast. Some light rain is forecast overnight. Up around 900 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. Overnight lows of about 4°C at 900 m.

Overnight rain2.0 mmOpen ground · 600 m15 mph · gusts 27 mphMorning pack-upDampness possible

Moon overnight

Waxing gibbous moon

Illuminated disc
80%
Moonrise
Outside this window
Moonset
02:59 next morning BST

Cloud and terrain vary across the area. Illumination describes the sunlit part of the Moon, not brightness at your pitch.

Overnight window: 21 Oct, 17:00 BST to 22 Oct, 08:00 BST. Approximate open-horizon times; hills can hide the Moon. Still take a headtorch.

Representative location: 56.386, -4.540. Times vary across the area.

300 m64 · mixed
Wind / gust
12 mph / 23 mph
Coldest
6.1°C
In cloud
0% of modelled night
Condensation
High
600 m58 · mixed
Wind / gust
15 mph / 27 mph
Coldest
6.1°C
In cloud
0% of modelled night
Condensation
High
900 m51 · mixed
Wind / gust
17 mph / 32 mph
Coldest
3.5°C
In cloud
72% of modelled night
Condensation
High

Open-hillside guidance across representative hills. Local shelter, ridges, tent design and the exact pitch can change conditions substantially. Read about sleeping-bag comfort ratings, pitching in strong winds or using the wild-camping forecast.

Daytime · exposed rockClimbing & scramblingBetaSub-zero temperatures and moisture may leave icy patches on exposed rock. Wet rock is likely. Gusts near 40 mph may affect balance on exposed rock. 13Poor · Very poor View detailsHide details
Regional rock conditions · sampled mountain terrain

Regional climbing & scrambling outlook

A broad guide to dampness and exposed rock across the area, not a forecast for every crag. Lower, sheltered crags and individual rock types may behave differently.

Conditions for exposed scrambling across the area look very poor (13/100). Rain is likely to leave rock wet. Polished slabs, vegetation and drainage lines may be notably worse. Gusts may reach about 40 mph on exposed ground, making crosswinds an important route consideration. Mapped summit-point geology across the representative hills includes psammite, pelite or semipelite, volcanic rock and granite, gneiss or gabbro. Rock can therefore respond differently to moisture between crags and routes.

Rock surfaceWet rock likelyExposed gust42 mphRain1.3 mm
Mapped rock across sampled summits3 broad familiesSummit samples, not a survey of every crag
psammite, pelite or semipelite 62% 5 representative summitsDry quartz-rich bands can be grippy, while mica-rich or foliated sections, lichen and vegetation may become slippery when wet.volcanic rock 25% 2 representative summitsOften grippy when dry, but volcanic rocks vary widely; wet lichen, smooth holds and local seepage can still make them slippery.granite, gneiss or gabbro 12% 1 representative summitGenerally grippy when dry and often still positive when damp, but wet slabs, lichen, polish and drainage lines can remain slippery.

Representative summit-point samples across the region; individual crags and routes may differ.

Generic exposed hands-on-rock terrain across representative summits; mapped summit-point geology is a broad regional sample, not a named-route survey. Contains British Geological Survey materials © UKRI 2026. How to use the climbing and scrambling forecast.

Recommended kit for this dayWeather-aware packing prompts, plus your core hillwalking kitView kit

For a day hillwalk, not a complete route-specific checklist. Carry navigation and backup you can use, warm and waterproof layers, suitable footwear, food and water, a headtorch, emergency shelter, first aid and a way to call for help. Snow, ice, technical terrain and overnight trips need additional equipment and skills.

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Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.

Updated 15 October 2026 at 05:28 UTC. See typical weekly and monthly conditions for Argyll and Loch Lomond.

More context for your hill day

Check the approach as well as the tops

Compare midge conditions by day and height, or look for a possible cloud inversion. For Snowdon and Tryfan, camera-derived cloud-base observations add a view of conditions already seen on the slopes.