Perthshire Midges in September — Risk, Peak Times, Kit
Noticeable at dawn and dusk. Repellent recommended. A buffer zone between worst (west) and best (south-east). Big Perthshire — Atholl, Rannoch, Tay forest — has plenty of midges but the open glens and farmland of Strathmore and the Ochils stay manageable.
Current risk
Perthshire in September: Moderate. Noticeable at dawn and dusk. Repellent recommended.
When they bite
Peak biting windows are dawn 6–8am and dusk 6–9pm. First proper cool nights typically in the second week. Population dropping rapidly through the month. Sheltered enclosed glens slower to clear than open ridges. East-side dryness brings the season to a close marginally earlier than the west.
What to wear
- Smidge repellent (75ml)
- Light-coloured long-sleeve baselayer — midges have a strong preference for dark clothing.
Tactical notes
September is the prize month for Perthshire. The first week typically still has summer-tier pressure in the sheltered enclosed glens (Glen Lyon at Pubil, Glen Tilt north of Forest Lodge, Loch Rannoch road); from the second week the bracken starts to colour across the Lawers slopes and the Atholl bracken, and the midge population drops sharply; by the third week the standard Perthshire trips are back on the table on midge grounds; by the last week the season is essentially over across the region.
This is the connoisseur's window for the Perthshire long routes. The full [Cateran Trail](/long-distance/cateran-trail) 103km Blairgowrie loop is at its best in September: bracken colour through Strathardle and Glenshee, dry firm farmland tracks, clean midge pressure. The [Rob Roy Way](/long-distance/rob-roy-way) from Drymen to Pitlochry is similarly excellent. The full [Glen Lyon](/glens/glen-lyon) road-to-road traverse, the [Glen Tilt](/glens/glen-tilt) corridor from Blair Atholl to the Cairngorms boundary, and the [Glen Lochay](/glens/glen-lochay) round all give multi-day September Perthshire trips with manageable insect tax.
For hill days, the Lawers range with September bracken colour and the An Stuc–Meall Garbh scrambling link in stable autumn conditions is one of the finest long Perthshire days available. The Carn Mairg round above [Glen Lyon](/glens/glen-lyon), the [Beinn a' Ghlo](/hillwalking/munros/beinn-a-ghlo-carn-nan-gabhar) three-Munro Atholl round from Blair Atholl, the Bridge of Orchy Munro cluster — all at peak September condition. [Schiehallion](/hillwalking/munros/schiehallion) with autumn light is the most-photographed Perthshire summer day. [Ben Vrackie](/hillwalking/corbetts/ben-vrackie) above Pitlochry, [Ben Chonzie](/hillwalking/munros/ben-chonzie) from Crieff, and the lower Perthshire Corbetts ([Farragon Hill](/hillwalking/corbetts/farragon-hill), [Auchnafree Hill](/hillwalking/corbetts/auchnafree-hill), [Meall Tairneachan](/hillwalking/corbetts/meall-tairneachan)) all give shorter clean days. If you only get one Perthshire visit a year, target the second half of September.