Definition of "northwind"

[…] promising to surrender them whenever they should be summoned by a fleet that should sail to them [the Pelasgians of Lemnos] from Attica in one day with a northwind.

1846, Connop Thirlwall, The History of Greece, Volume II, New Edition, Longman et al. (publishers), page 264

[...] and notwithstanding the cutting blasts of a northwind, and the sharp driftings of the half-frozen snow, [...]

1882, Charles Lever, chapter XXXI, in The Daltons; or, Three Roads in Life, page 145

To illustrate more fully, if an author managed over a certain number of his pages to produce a feeling of sultriness, or oppression, in the reader, this would unconsciously awaken in the reader the desire for a cold, fresh northwind — and thus some aspect of a northwind would be effective if called forth by some aspect of sultriness.

1968, Kenneth Burke, Counter-Statement, page 39