JULY was originally christened in its present form by Mark Antony, who in 44 BC names it after his former co-consul Julius Caesar. Before that it was called Quintilis, the "fifth month", which seems a little disingenuous because, if you count them up on your fingers, you will realise that July is in fact the seventh month of our year. But then the Roman calendar began in March, which accounts not only for the Quintilian anomaly, but also for September being its seventh month, October is eight, and so on.
There is a richness about the sky in July which far surpasses that of any other month. July skies have a unique wealth of detail and variety, perhaps stemming from the accumulated warmth, or maybe associated with the typically high water vapour content of the atmosphere around this time. One day the sky may be characterised by a deep blue, relieved by a complex pattern of white fleecy cirrus clouds; another by an array of dark, threatening cumulonimbus, giving clear warning of impending hail or thunder; and on a third the grey monotony of a thoroughly wet day may break just in time to reveal a wild, lurid and fantastic sunset, unmatchable for its complexity and wealth of coIouring. And a wet July, particularly, causes the vegetation to assume a vividness of tint far exceeding that which may be displayed at any other time of year.
The temperature on an average July day in Ireland rises to about 20 degrees Celsius by mid-afternoon, and in a few memorable Julys the temperature has soared once or twice to 32 or 33 degrees. At the other end of the scale, ground frost is very rare during this month: it has occurred once or twice, but is so infrequent as to be considered almost a freak occurrence.
It is usually a duller month than June; the average July day has between 4 and 6 hours sunshine - about an hour less than the equivalent figure for last month. The decrease is caused in part by the fact that the days are becoming shorter again, but it also reflects the more cloudy conditions to which this month is prone. The enhanced power of the summer sun around this time often results in a rise in pressure over the Atlantic and a corresponding fall over the continent - almost like the sea breeze effect on a continental scale. The consequence is a more westerly flow of wind over Ireland and a moist air-flow which brings with it more cloud compared to previous months, higher relative humidity and usually an increase in rainfall.