Marlborough's weather: June 2017 - simply a record breaking month
June was a memorable month for a number of meteorological reasons - not least the breaking of temperature records at this weather station that was started in 1984…a better month for butterflies.
On June 19 the mini heat wave boosted the thermometer to a thirty-three year record for this station with a maximum of 31.4C. Just two days later, at the peak of the hot weather, the temperature soared again to a maximum of 32.2C. This was 12.5C above the long-term average for June.
The average minimum temperature was 11.74C being 2C above the long-term average with a similar value of +1.9C for the daytime average.
Although the warmth gradually dissipated after this hot spell it was a record breaking month with the mean temperature 1.95C above the long-term average breaking the previous record set in 2006 by 0.1C.
Living at these latitudes and in our unique position geographically, being close to the continental land mass and large areas of water, we are used to wide fluctuations in the day to day and day to night temperatures. On June 18 there was a variation of 19.7C between day and night time extremes yet ten days later, on June 28, the variation was just 2C.
Turning to the rainfall, it was another below average month - the fifth so far this year. The total was 35.0mm, being 64 per cent of the long-term average or a monthly deficit of 20mm. The last six months have produced a deficit of 79mm (or over three inches) compared to the long-term average.
We have also experienced five consecutive years of below average June rainfall totals following the extreme amount of 127.9mm in 2012. The record of 143.2mm was set in 1998 and - by contrast - June in 1995 was a very dry month with just 12.5mm.
It is important to remember that much moisture from ground sources and plant life evaporated during each day with in excess of 5mm of equivalent rainfall on two days. The total evaporation for the month was 96.8mm - almost three times the total rainfall for June.
Strong sunshine amounted to 128 hours which was 10 hours below the average for the last three years when this instrument was installed.
Solar energy was just above the seven-year average with a figure of 102 per cent.
The UV levels have varied throughout the month from 2.9 (Low) during the miserable day on June 28 to 10.4 (Extreme) that occurred briefly on the June 24. This latter level has only been recorded once before since this instrument was installed in the autumn of 2009 - that was in June 2011,.
Not surprisingly, the average soil temperature (17.7C) at a depth of 5cm was 2.4C above the average for this thermometer that was installed in 2014.
I think the quotation from Gertrude Jekyll, the influential British horticulturist, garden designer, artist and writer who created over 400 gardens in the United Kingdom, is appropriate to describe the past month: “What is one to say about June, the time of perfect young summer, the fulfilment of the promise of the earlier months and with as yet no sign to remind one that its fresh young beauty will ever fade.”