October saw contrasts & fluctuations in Marlborough’s weather – and only about half the average rainfall

October brought Marlborough another month of contrasts with some daytime temperatures more likely to occur in August, and then at the end of the month we briefly endured a record severe frost with temperatures more likely to be seen in the months of January or February.

The mean temperature for the month was 0.6C below the 34-year average, principally due to cool nights. The daytime mean was 0.5C above average whereas the night mean was 1.6C below average.

The second week saw two days that reached maxima in the 20’s with 22.4C and 21.3C on October 10 and 13 respectively. In contrast, the during the early hours of October 31 the thermometer fell steadily to a minimum of -4.3C.   This was record-equalling for this station, which was set up in 1984.  The same minimum occurred on October 30 1992.

A record for the coldest October day since the station began was set on October 27 when the thermometer resolutely refused to rise above 5.2C due to strong northerly winds. The October average maximum is 14.7C.

 

Another example of how variable our weather can be, is seen in the months’ mean temperatures.  For October 2018 was 9.87C.  But in 1992 we experienced a very cool month with a mean of just 6.95C whereas a balmy October occurred in 2001 when the recorded mean was 12.77C.  Tricky for the birds and bees to keep with such fluctuations.

Turning to rainfall, we have experienced the fourth consecutive below average October rainfall. The total for the month was just 44.6mm, which was 53 per cent of the 34 year average or 40.2mm below. The wet October of 2004 produced 159.3mm whereas the very dry October in 2017 gave us only 31.3mm when the average stands at 84.8mm. 

There were two very wet days on October 14 and 15 with 12.7mm and 14.8mm respectively. However, we enjoyed 22 dry days against the average of 14 dry days.

October 2018 was a very sunny month as we enjoyed 130 hours of strong sunshine that contrasts with the average for the previous four years of 73 hours. My sunshine recorder was only installed in 2014.

Still on the theme of contrasting weather, the diurnal data for October shows just how much we as individuals have to adjust on a daily basis. The minimum temperature variation between day and night on October 6 was just 2C whereas a range of 17.3C occurred on October 31 as the severe frost rapidly cleared during the morning with the arrival of a gentle southerly air mass.

This quotation from Percy Shelley sums up another colourful season: “There is a harmony in autumn, and a lustre in its sky, which through the summer is not heard or seen, as if it could not be, as if it had not been!”

There is more detailed information with daily reports on Eric Gilbert’s Windrush Weather station website.