Weather changes very often

Main article: Etymology of Scotland
Scotland comes from Scoti, the Latin name for the Gaels. Philip Freeman has speculated on the likelihood of a group of raiders adopting a name from an Indo-European root, *skot, citing the parallel in Greek skotos (σκότος), meaning "darkness, gloom".^[32] The Late Latin word Scotia ("land of the Gaels") was initially used to refer to Ireland,^[33] and likewise in early Old English Scotland was used for Ireland.^[34] By the 11th century at the latest, Scotia was being used to refer to (Gaelic-speaking) Scotland north of the River Forth, alongside Albania or Albany, both derived from the Gaelic Alba.^[35] The use of the words Scots and Scotland to encompass all of what is now Scotland became common in the Late Middle Ages.^[22]
Prehistory
Main article: Prehistoric Scotland
See also: Timeline of prehistoric Scotland
Repeated glaciations, which covered the entire land mass of modern Scotland, destroyed any traces of human habitation that may have existed before the Mesolithic period. It is believed the first post-glacial groups of hunter-gatherers arrived in Scotland around 12,800 years ago, as the ice sheet retreated after the last glaciation.^[36] At the time, Scotland was covered in forests, had more bog-land, and the main form of transport was by water.^[37]: 9 These settlers began building the first known permanent houses on Scottish soil around 9,500 years ago, and the first villages around 6,000 years ago. The well-preserved village of Skara Brae on the mainland of Orkney dates from this period. Neolithic habitation, burial, and ritual sites are particularly common and well preserved in the Northern Isles and Western Isles, where a lack of trees led to most structures being built of local stone.^[38] Evidence of sophisticated pre-Christian belief systems is demonstrated by sites such as the Callanish Stones on Lewis and the Maes Howe on Orkney, which were built in the third millennium BC.
The first written reference to Scotland was in 320 BC by Greek sailor Pytheas, who called the northern tip of Britain "Orcas", the source of the name of the Orkney islands.^[37]: 10 During the first millennium BC, the society changed dramatically to a chiefdom model, as consolidation of settlement led to the concentration of wealth and underground stores of surplus food.^[37]: 11
The Roman conquest of Britain was never completed, and most of modern Scotland was not brought under Roman political control.^[40] The first Roman incursion into Scotland occurred in 79 AD, when Agricola invaded Scotland; he defeated a Caledonian army at the Battle of Mons Graupius in 83 AD.^[37]: 12 After the Roman victory, Roman forts were briefly set along the Gask Ridge close to the Highland line, but by three years after the battle, the Roman armies had withdrawn to the Southern Uplands.^[41] Remains of Roman forts established in the 1st century have been found as far north as the Moray Firth.^[40] By the reign of the Roman emperor Trajan (r. 98–117), Roman control had lapsed to Britain south of a line between the River Tyne and the Solway Firth.^[42] Along this line Trajan's successor Hadrian (r. 117–138) erected Hadrian's Wall in northern England^[37]: 12 and the Limes Britannicus became the northern border of the Roman Empire.^[43][44] The Roman influence on the southern part of the country was considerable, and they introduced Christianity to Scotland.^{[37]: 13–14 [39]: 38}
The Antonine Wall was built from 142 at the order of Hadrian's successor Antoninus Pius (r. 138–161), defending the Roman part of Scotland from the unadministered part of the island, north of a line between the Firth of Clyde and the Firth of Forth. The successful Roman invasion of Caledonia 208–210 was undertaken by emperors of the imperial Severan dynasty in response to the breaking of treaty by the Caledonians in 197,^[40] but permanent conquest of the whole of Great Britain was forestalled by the death of the senior emperor Septimius Severus (r. 193–211) while on campaign at Eboracum (York), and the Caledonians were again in revolt in 210–211.^[40] Forts erected by the Roman army of the Severan campaign were placed near those established by Agricola and were clustered at the mouths of the glens in the Highlands.^[40]
To the Roman historians Tacitus and Cassius Dio, the Scottish Highlands and the area north of the River Forth was called Caledonia.^[40] According to Cassius Dio, the inhabitants of Caledonia were the Caledonians and the Maeatae.^[40] Other ancient authors used the adjective "Caledonian" to pertain to anywhere in northern or inland Britain, often mentioning the region's people and animals, its cold climate, its pearls, and a noteworthy region of wooden hills (Latin: saltus) which the 2nd-century AD Roman philosopher Ptolemy, in his Geography, described as being south-west of the Beauly Firth.^[40] The name Caledonia is echoed in the place names of Dunkeld, Rohallion, and Schiehallion.