You will have checked the forecast. It said sun, 19°C, light winds. You will have driven to the coast and arrived in a grey wall at 12°C with a hundred metres of visibility, and you will have checked the forecast again, and it will still say sun, and you will begin to question several things.
This is the haar, and the reason nobody warned you is that it is genuinely difficult to forecast at the resolution that matters to a person choosing a beach.
What it is
Advection fog. In late spring and summer the land warms up while the North Sea stays cold — surface temperatures around 11 to 13°C well into July. Warm, moist air moving over that cold water is chilled from below past its dew point, and the moisture condenses into a dense, low fog sitting on the sea.
An easterly breeze then pushes it ashore. It can arrive in twenty minutes. It typically penetrates a mile or two inland before the warmer land eats it, which is why you can stand in it at the beach and see blue sky over the hills behind you.
Haar in practice
- Season: April to August, worst in May and June
- Wind direction: anything with east in it. A westerly, and you are fine
- Temperature drop: commonly five or six degrees within the fog
- Depth inland: usually one to three miles; sometimes it sits offshore all day and never lands
- Timing: often clears late morning, then returns in the evening as the land cools
How to beat it
Go west, or go up. Both work, and they work quickly. If the coast at Stonehaven is fogged, twenty minutes inland is very often in full sun. The Deeside valley, the Cairngorms foothills and anywhere over a couple of hundred metres are the standard escapes.
Check the wind direction rather than the sunshine symbol — it is the single most useful indicator, and it is on every forecast. Coastal webcams are better still, and most harbour towns have one.
And take a jacket regardless of the temperature at the car. This is the part visitors get wrong most consistently: it was 19°C where you parked, so the jacket stayed in the boot, and the boot is now a mile away.
“It has its own weather and it does not consult anybody. I have seen a wedding party go from photographs to nothing in the time it takes to arrange them.”
A retired fisherman in a north east harbour town
Or just enjoy it
It is genuinely beautiful, if you did not have plans. The foghorn note, the town emerging in pieces, the way sound goes flat and close. Photographers come for it deliberately.
Locals mostly regard it as an old relative who visits without warning and stays slightly too long. You are allowed to be annoyed. You are not allowed to be surprised twice.
