![Haar rolling in over the Forth Bridge](https://upload.wikimedia.org/wikipedia/commons/e/e9/Haar_rolling_in_over_the_Forth_Bridge.jpg)
In
meteorology
Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...
, haar or sea fret is a cold
sea fog. It occurs most often on the east coast of Great Britain between April and September, when warm air passes over the cold
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
.
The term is also known as harr, hare, harl, har and hoar.
Causes
Haar is typically formed over the sea and is blown to the land by the wind. This commonly occurs when warmer moist air moves over the relatively cooler North Sea causing the moisture in the air to condense, forming haar.
Sea breezes
A sea breeze or onshore breeze is any wind that blows from a large body of water toward or onto a landmass; it develops due to differences in air pressure created by the differing heat capacities of water and dry land. As such, sea breezes ar ...
and easterly winds then bring the haar into the east coast of Scotland and North-East England where it can continue for several miles inland. This can be common in the UK summer when heating of the land creates a sea breeze, bringing haar in from the sea and as a result can significantly reduce temperatures compared to those just a few miles inland.
Nomenclature
The term ''haar'' is used along certain lands bordering the
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
, primarily eastern
Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
and the north-east of England. Variants of the term in
Scots and northern English include har, hare, harl, harr and hoar. Its origin is related to
Middle Dutch
Middle Dutch is a collective name for a number of closely related West Germanic dialects whose ancestor was Old Dutch. It was spoken and written between 1150 and 1500. Until the advent of Modern Dutch after 1500 or c. 1550, there was no overarch ...
''haren'', referring to a cold, sharp wind.
[Michiel de Vaan (2014-2018), Addenda EWN: haren] In
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
and
Northumberland
Northumberland () is a county in Northern England, one of two counties in England which border with Scotland. Notable landmarks in the county include Alnwick Castle, Bamburgh Castle, Hadrian's Wall and Hexham Abbey.
It is bordered by land on ...
it is commonly referred to as a sea fret.
References
Environment of Scotland
Fog
Scottish coast
Climate of Scotland
North Sea
Scots language
Scottish words and phrases
{{climate-stub