You check the weather before you head into the hills. Everyone does. Temperature, rain, wind — the basic conditions that determine what you wear and whether you go at all.
But the weather forecast doesn't tell you about midges. And the absence of midges from the weather forecast has led to a significant amount of entirely avoidable suffering.
Here's why they're different things, and why you need both.
What a weather forecast tells you
A standard weather forecast — Met Office, BBC Weather, your preferred app — gives you temperature, precipitation probability, wind speed and direction, cloud cover, and UV index. These are the variables that determine whether your day on the hill is comfortable, wet, cold, or spectacular.
None of them, individually, tells you whether midges will be a problem.
This is not an oversight. Midge activity is determined by a specific combination of conditions that doesn't map neatly onto the standard weather summary. "Warm and cloudy with light winds" sounds like a pleasant summer day. In midge terms, it is a five-alarm situation.
What a midge forecast tells you
The Midge Activity Index combines the variables that specifically drive midge behaviour:
Wind speed is the dominant factor. Midges ground themselves above approximately 7mph. Any forecast that shows sustained wind above this threshold is, from a midge perspective, a good day regardless of everything else.
Temperature affects activity — midges are most active between 10°C and 20°C. Below 7°C they become largely inactive. Above 22°C in direct sun, the conditions suppress them, though in Scotland this temperature is more theoretical than common.
Humidity and recent rainfall drive breeding cycles. A wet spring followed by warm, still early summer produces the conditions for a heavy first generation in June. Drought years can reduce numbers; wet years amplify them.
Cloud cover removes the sunlight inhibition that keeps midges grounded during the middle of the day. Overcast conditions extend their active window considerably.
The forecast index combines these factors to produce a single daily score for each location — not a guarantee, but an informed probability based on real local weather data.
Why this matters in practice
The scenario the Hooligan sees repeatedly: a walker checks the weather, sees light rain clearing to cloud with a temperature of 14°C and 5mph winds. Sounds manageable. Packs accordingly.
5mph is below the midge flight threshold. 14°C and cloudy is ideal midge weather. Light rain has recently topped up standing water. The midges are delighted.
The weather forecast was accurate. It simply wasn't designed to answer the question: will today be comfortable to be outdoors?
That's a different question, and it requires a different tool.
How to use both
Check the weather forecast for: what to wear, whether to go, route conditions.
Check BiteForecast for: when to go, where to stop for lunch, whether the evening descent will require protection.
Used together, they give you the full picture. Used separately, one of them has a significant gap in it.
Check the BiteForecast Midge Activity Index — 20 Highland locations, updated daily → BiteForecast.scot