Marlborough swelters with record overnight temperature

Written by Eric Gilbert on .

Marlborough dawn - pic Eric GilbertMarlborough dawn - pic Eric GilbertYesterday was the hottest day this year in Marlborough when the thermometer soared to 31.9C just after 4.30pm. Last year the hottest July day occurred on the 1st with a maximum of 32.6C although the record was set on 19th July 2006 with a peak temperature of 35.1C.

Also memorable yesterday was the continuous strong (100watts/m2.) sunshine that totalled 15.79 hours. This is the highest number of hours recorded this year and beats the previous high set on 30th June last year.

Broken cloud moved across during the evening that reduced the radiation of the extreme heat from the ground into the atmosphere that produced a very warm night with a minimum of 20.4C. just after 5.30am.  This is a record for my station that started operating in 1984, the previous high being set on 20th July 2006.  By 8.00 am today the thermometer had risen a little to 21.2C.

Due to the minimal rainfall and higher temperatures over the last four days the soil temperature at a depth of 5cm rose to 23.1C at 8.00am.

This month we have had very little precipitation; the total for the first 19 days is 10.4mm, which is a fraction of the mean for July of 61.0mm.  Not surprisingly, the total for the equivalent rainfall lost through evaporation from plant life, water surfaces and the ground is 55mm giving a deficit so far this month of 45mm.