Perthshire Midges in May — Risk, Peak Times, Kit
Background pressure only. Head net optional. 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 May: Low. Background pressure only. Head net optional.
When they bite
Peak biting windows are dawn 6–8am and dusk 5–7pm. First proper warmth across the region. Sheltered glen floors and lochsides reach midge emergence threshold in the last week. Higher ground and east-side rain-shadow advantage keep biting pressure much lower than the equivalent west-coast week.
What to wear
- Smidge repellent (75ml)
- Light-coloured long-sleeve baselayer — midges have a strong preference for dark clothing.
Tactical notes
May in Perthshire is the most subtle transition month in the Highlands. The east-side rain-shadow advantage and slightly later spring mean midge emergence runs a week to ten days behind the equivalent west-coast latitude. The first three weeks are typically still clean across the region. The last week often delivers the first emergence in the canonical sheltered traps: the bog flats along the Loch Tay shore, the head of [Glen Lyon](/glens/glen-lyon) at Pubil, the Loch Rannoch lay-bys at the Camusericht end, and the [Glen Tilt](/glens/glen-tilt) river meadow north of Forest Lodge.
This is the last clean window for the long enclosed-glen walks. The full [Glen Lyon](/glens/glen-lyon) road-end to road-end day, the [Glen Tilt](/glens/glen-tilt) corridor from Blair Atholl, the [Cateran Trail](/long-distance/cateran-trail) (Blairgowrie loop through the Strathardle and Glenshee farmland), the [Rob Roy Way](/long-distance/rob-roy-way) east end from Strathyre to Pitlochry — all manageable with a 75ml Smidge as insurance.
For hill days, the Lawers range is at its best of the year in May. The seven-Munro full traverse, the shorter [Meall nan Tarmachan](/hillwalking/munros/meall-nan-tarmachan) and Tarmachan Ridge round, the Carn Mairg Glen Lyon north-side round ([Carn Mairg](/hillwalking/munros/carn-mairg), [Carn Gorm](/hillwalking/munros/carn-gorm), [Meall Garbh](/hillwalking/munros/meall-garbh-nn647516), [Meall na Aighean](/hillwalking/munros/meall-na-aighean)) — all on long-daylight late-spring days with minimal insect tax. The Glen Lyon south-side Munros [Stuc an Lochain](/hillwalking/munros/stuc-an-lochain-stuchd-an-lochain) and [Meall Buidhe](/hillwalking/munros/meall-buidhe-fife-perthshire) give a quiet round. [Schiehallion](/hillwalking/munros/schiehallion) is at its busiest visitor density of the year but the wind exposure on the summit ridge keeps it midge-free. [Beinn a' Ghlo](/hillwalking/munros/beinn-a-ghlo-braigh-coire-chruinn-bhalgain) and the Atholl bothies — [Allt Scheicheachan](/bothies/allt-scheicheachan) at the foot of the round — work cleanly. The Bridge of Orchy ridge ([Beinn Dorain](/hillwalking/munros/beinn-dorain), [Beinn an Dothaidh](/hillwalking/munros/beinn-an-dothaidh), [Beinn Achaladair](/hillwalking/munros/beinn-achaladair), [Beinn a' Chreachain](/hillwalking/munros/beinn-a-chreachain)) is the westernmost Perthshire option.