"My tablets!" says Prince Hamlet. "Meet it is I set it down."
As far as we know Hamlet did not take his own advice literally, but many others did. Over the centuries, many people recorded the daily happenings of their lives, and years afterwards their diaries have provided rich pickings for climatologists as they rummage endlessly for bits and scraps of information about the weather of the past.
Diaries, whatever their length or the quality of any meteorological information they contain, nearly always have a common feature: they begin on New Year's Day. And that of perhaps the most famous diarist of them all was no exception.
Samuel Pepys began his diary on January 1st, 1660, when he was 27 years old, and kept it faithfully for nearly a decade.
A few days after beginning his chronicle, on January 16th, 1660, Pepys tells us of the hourly weather reports provided for the citizens of London: "I stayed up till the bellman came by with his bell just under my window and cried `Past one of the clock, and a cold, frosty, windy morning'."
And by January 21st, 1661, he was wondering if something funny was happening to the London climate: "It is strange what weather we have had all this winter; no cold at all, but the ways are dusty, and the flies fly up and down, and the rose bushes are full of leaves, such a time of the year as was never known in this world before."
Here in Ireland, the earliest reference to weather in a written document is probably a report in the Annals of the Four Masters of a vicious storm on Lough Conn, believed to have occurred in 2668 BC. The earliest weather journal proper that we know of is a weather diary for Kilkenny for 1682 and 1683 kept by an employee of the Duke of Ormonde.
The diarists were more prolific in the following century: Thomas Neve of Ballyneilmore in Co Derry chronicled the elements from 1711 until 1725; James Simon documented the period from 1753 to 1755; Dr John Rutty summarised Dublin weather from 1716 to 1766; and the Rev Henry Ussher maintained a weather register at Dunsink Observatory from 1786 to 1790.
A Huguenot immigrant to Dublin called Maximillian Faviere carried the story into the next century with regular weather diaries from 1781 to 1812.
All these accounts of the weather are descriptive, but over the years climatologists have evolved clever techniques which allow them to relate the descriptive reports to numerical values in a surprisingly accurate and consistent way.