When is midge season in Scotland?

Typically May until September.

Midges begin to emerge during May (usually mid-late May). These are typically the non-biting boys. When the biting females arrive in early June the season truly kicks off. Traditionally, our largest catches (in Midge Forecast traps) have always been the first week of June. Midge season then runs until early/late September.

How does the weather affect midges in Scotland?

Weather midges LOVE
  • A warm, damp spring.
    This kind of Spring weather will see midge numbers rocket.
  • Still, humid conditions
  • Dawn, dusk and cloud cover
    When sun’s irradiance (or penetration through cloud) reduces to below 260 W/m2 the midges come out to play. When it drops below 130 W/m2 it’s all-you-can-eat buffet time.
  • A warm, wet Summer/Early Autumn
    Often we see a 3rd generation.
  • A harsh winter has little or no effect.
    They are well protected below the soil’s surface.
Weather midges HATE
  • A cold, dry spring.
    It delays the arrival of the first generation.
  • Wind.
    Midges have tiny wings and can’t fly in wind over 7mph.
  • Sunny days.
    Sunlight suppresses midge activity.
  • Dry, hot June/early July.
    Reduces the survival of the second generation.

Where do midges go in winter?

Eggs from second-generation adults usually mature to final stage larvae, then take cover a few centimetres below the soil surface for winter. During that time it’s thought they migrate up and down through the soil over a daily cycle and have a quiet munch on decaying organic matter to keep them going.

The Scottish midge lifecycle