Weather, communication, code, interpretation, influence: these things have always gone together. For both Seneca and Aristotle, the airy region was a region of conveyance, of transferral and translation, in which "meteors" or atmospheric phenomena... were produced by the influence of the celestial sphere on the sublunary one. For Virgil, too, weather told a coded tale of influence, of cause and effect, and hence was decryptable: his Georgics describes a world of signs in which the movement of ants, swallows, frogs, and ravens can be read and interpreted as can the appearance of the clouds, sun and moon. Seventeenth-century English Puritans treated the sky as a switchboard connecting them to God, divining the portents in its storms and lightshows. The anonymous author of the 1641 text A Strange Wonder, or, The Cities Amazement (subtitled News from Heaven) describes exceptional meteorological events as God's "signes and Tokens," "prodigious ensignes," "ominous harbingers," "Cyphers," "notable Messengers." Londoners were so addicted to such Cyphers that, according to Defoe, during the plague years they scoured the clouds constantly for "shapes and figures, representations and appearances." It's standard to think of the atmosphere as a medium... but we should go further. Weather is and always has been more than just a medium: it is also media.
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When language grapples with the weather there is slippage and there is displacement. Johnson's quip that "when two Englishmen meet, their first talk is of the weather" is an easy one to make; Gwendolen's intuition (in Wilde's The Importance of Being Earnest) that "whenever people talk about the weather, I always feel quite certain that they mean something else" is much more astute. For centuries manuals and charts have tried to map meteorological phenomena onto social ones, from The English Chapmans and Travellers Almanack for The Year of Christ 1697 (which aligns the ten-week frost with the gunpowder plot, the time when "the whole heaven seemed to burn with fire" with the invention of the art of printing) to Election Weather Tables compiled by today's Met office (Labour only wins in fair weather, apparently; that fateful day in 1979 was foul) or the Weather-to-Stock Market Correspondence Graphs studied by the more esoteric among our economists. The weather unfolds endlessly across non-meteorological discourses, across Other Stuff. It's an index both of truth and of all that's random, meaningless. Like all media, it bears a plethora of messages - perhaps even the message - while simultaneously supplying no more than conversational, neutral white noise.
-- Tom McCarthy, Meteomedia, or Why London's Weather Is in the Middle of Everything