Lochaber Midges in September — Risk, Peak Times, Kit
Hard going at dawn and dusk. Head net essential outdoors. Ground zero for Scottish midges. Wet, sheltered, west-coast — the trinity that drives the biggest populations in Britain. Glen Nevis, the Mamores, Knoydart and the Road to the Isles are all peak-pressure habitat from late May to mid-September.
Current risk
Lochaber in September: High. Hard going at dawn and dusk. Head net essential outdoors.
When they bite
Peak biting windows are dawn 6–8am and dusk 6–9pm. Cooling decisively, especially overnight. First proper night frosts at altitude usually arrive in the second week. Midge population starts a sustained decline; by the end of the month numbers are perhaps a third of mid-summer peak.
What to wear
- Smidge repellent (75ml)
- LifeSystems head net
- Light-coloured long-sleeve baselayer — midges have a strong preference for dark clothing.
Tactical notes
September is the month of relief in Lochaber. The first cold night at altitude — usually the first week of the month — starts knocking the adult population back, and by mid-month the difference is noticeable to anyone who's been in the region all summer. By the last week, an evening at the [Glen Nevis](/glens/glen-nevis) campsite in still weather is plausibly tolerable; in mid-August it was unworkable.
The decline runs from the top down. The Mamore ridge, the Aonachs, the [Ben Nevis](/hillwalking/munros/ben-nevis-beinn-nibheis) approaches all clear out first. Glen Nevis valley floor takes longer, especially below the gorge in the warmest spots. Knoydart and the [Sourlies](/bothies/sourlies) / [Barrisdale](/bothies/barrisdale) bothies hold significant pressure into the third week. Loch Quoich camps are tolerable at the end of the month, hostile at the start.
This is the best month for serious multi-day Lochaber trips. Long enough days (still over 11 hours at end of month), proper autumn colour starting in the birches, low tourist numbers compared to August, midges in retreat. Recommended: Knoydart traverses (the classic Inverie circuit takes in [Ladhar Bheinn](/hillwalking/munros/ladhar-bheinn) and [Sgurr na Ciche](/hillwalking/munros/sgurr-na-ciche)), the Loch Ossian / Loch Treig overnight, the Glen Nevis to Corrour foot route, the Mamore Round, the Ring of Steall. [Cape Wrath Trail](/long-distance/cape-wrath-trail) through-hikers traditionally hit Knoydart in September for exactly these reasons.
Kit for the first half of September: full peak (head net, Smidge, long sleeves, sealed tent). For the second half: head net and Smidge in the pack, used selectively rather than continuously. By the very end of the month the kit comes off for most situations except dusk camps below 400m.