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

Thursday 15 October 2026 · The Arrochar Alps, Crianlarich and Argyll hills

Confidence: Medium Why?

Uncertainty over high-ground wind strength. Uncertainty over sky cloud cover and sunshine.

What matters most

A poor day on the tops in Argyll and Loch Lomond, with burns likely to be in spate and strong, gusty winds.

High-ground wind · 900 m25-35 mph westerly Gusts · 900 m40-50 mph Cloud base500-800 m Feels like · 900 m-6 to -2°C
Regional median

Sunshine and sky

Sunshine through the day. The time blocks show where the model places the brighter spells.

Modelled sunshine0.8 h6% of daylight
Early0 h sunshine
MiddayLess than 1 hour sunshine
Later0 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 · 08:00–12:00PoorSummit winds around 15-30 mph. Gusts around 35-45 mph are possible on exposed ground. Gusts this strong can make walking into it hard work, with buffeting on ridges and edges. Rain is forecast on some hills during this period. Cloud may restrict summit views early on. Rain is possible during the morning, but forecast models disagree on whether it will fall.
28
Afternoon · 12:00–17:00PoorMore rain is expected. Summit winds around 20-35 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. Rain is forecast on some hills during this period. Summit cloud is more likely to break later. Rain is possible during the afternoon, but forecast models disagree on whether it will fall.
16

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 westerly wind of 25–35 mph, gusting 40–50 mph, picking up through the day. Gusts like that are strong enough to knock you off balance, so take care near edges and on narrow ridges.

02

Walking impact

Gusts of 40–50 mph are strong enough to knock you off balance, so take care near edges and on narrow ridges.

03

Ground conditions

The ground is likely to be saturated after recent rain. Expect boggy paths and rapid runoff if more rain arrives.

04

Spate risk

High spate risk based on recent and forecast rainfall. Burns and unbridged crossings may become difficult or impassable. Timing and severity can vary between catchments. Check the peak forecast for the separate rain/runoff periods. Turn back if a crossing looks unsafe.

05

Rain and showers

Sleet is possible on the tops, and it could turn to snow if it is a little colder. Rain for much of the day. Expect 5–10 mm in total, measured as melted water, so any snow would lie deeper. Rain is possible during the morning and afternoon, but forecast models disagree on whether it will fall. On some hills, sleet is possible on the tops. Small temperature changes could shift the mix towards rain or snow. Visibility may drop briefly in showers in parts of the area.

06

Cloud-free summits

Clear-summit estimate: about 10% early, about 20% around midday and about 35% later.

07

Cloud and visibility

Expect many summits to be in cloud for most of the day. The cloud base could be as low as 400–700 m early in the morning. In cloud you'll be finding your way without landmarks, so carry navigation you trust and know how to use, with a backup such as a spare battery or a map and compass.

08

Temperature and wind chill

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

09

Freezing level

The freezing level is close to summit height.

10

Daylight

Sunrise 07:50, Sunset 18:18, about 10.5 hours daylight.

Overnight · 17:00–08:00Wild campingBetaToo windy for an exposed pitch up around 900 m on some hills (gusts of about 45 mph and about 5 mm of rain). Lower down, a mixed night to camp, mainly because of the wind. 39Poor · 600 m View detailsHide details
Regional night beginning Thursday 15 October 2026

Full regional overnight outlook

Too windy for an exposed pitch up around 900 m on some hills. Lower down, a mixed night to camp, mainly because of the wind. Gusts reach about 45 mph around 900 m and nearer 30 mph around 300 m, which makes for a noisy, testing night even in a good tent. Check the forecast for the hill and height you have in mind, and don't assume lower ground will be sheltered. About 5 mm of rain is forecast overnight. Above about 600 m you'd likely be in cloud for part of the night: damp, and hard to find your way if you need to move. A cold night, down to about 2°C around 900 m. The ground will be sodden after recent rain, so pick a firm, well-drained pitch.

Overnight rain5.2 mmOpen ground · 600 m21 mph · gusts 38 mphMorning pack-upDampness possible

Moon overnight

Waxing crescent moon

Illuminated disc
26%
Moonrise
Outside this window
Moonset
19:28 BST

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

Overnight window: 15 Oct, 17:00 BST to 16 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 m58 · mixed
Wind / gust
17 mph / 31 mph
Coldest
3.7°C
In cloud
0% of modelled night
Condensation
High
600 m39 · poor
Wind / gust
21 mph / 38 mph
Coldest
3.6°C
In cloud
73% of modelled night
Condensation
High
900 m19 · very poor
Wind / gust
24 mph / 44 mph
Coldest
1.7°C
In cloud
80% of modelled night
Condensation
High

The ground is likely to be very wet after recent rain. Expect boggy approaches and choose a durable pitch carefully.

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 & scramblingBetaWet rock is likely. Gusts near 45 mph may affect balance on exposed rock. 0Poor · 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 (0/100). Rain is likely to leave rock wet. Polished slabs, vegetation and drainage lines may be notably worse. Gusts may reach about 45 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 gust43 mphRain5.0 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 15:29 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.