July figures bear out warmer times

July’s weather figures have again indicated the Gisborne-East Coast region is heading to warmer, sunnier winters.

Last month added to the trend of warmer than usual months, and gave further proof of the long-term trend with its mean temperature totals.

In addition, although July is normally the district’s wettest month, the past 31 days produced an “average” July rainfall of just over 130 millimetres compared to the 1991-2020 average of 126mm.

Nonetheless, such rain as fell was enough to keep residents worried, with the ground still saturated and flooding at the drop of a hat.

The big surprise July delivered was the number of clear skies, with four days reaching eight hours of sunshine.

The sunniest day was on the 25th when residents enjoyed a very spring-like 8.5 hours of sun.

In the previous decade, 2013 holds the record for the sunniest run of days in July with an astonishing eight days getting over nine hours of sunshine — five of those in a row and the sunniest being the 29th with 9.2 hours of sun.

Back to last month: the more benign weather produced a mean daily maximum for July of almost 15.3 degrees — point nine of a degree above the 14.4 degree average for the time of year.

Although the clearer skies meant for greater heat loss overnight, the mean minimum daily temperature was still over 5.7 degrees, or a quarter of a degree warmer than usual.

Those clear skies gave frostier weather, and July had 13 mornings where the air temperature fell to zero or below, and two mornings hitting minus three degrees.

Even so, this was overall milder than 30 to 40 years ago, when frosts were much deeper and a more notable occurrence.

The end product of more sun, warmer days, normal rain and a swing to more west or north-west winds, was a mean monthly temperature of 10.5 degrees, or over half a degree warmer than usual.

Historical weather archives show the mean monthly temperature for July in Gisborne has risen steadily from 9.1 degrees over the 1937 to 1980 period.

Over the 30 years 1971 to 2000 the July average was 9.3, but had risen to 9.7 for the 1981 to 2010 period.

The latest 30-year average for 1991 to 2020 is 9.9 degrees — and to repeat, last month averaged a daily mean of 10.5.

For those interested in historical trends, the warmest July was only last year — with a mean daily average of 12.1 degrees.

Since official records started at Gisborne airport in 1937, July’s mean temperature has hit or exceeded 10.5 degrees only seven times, mostly in the past 25 years.