Dry July . . . also warmer,More sun too, as latest figures indicate accelerating trend

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

A sunnier, drier and warmer-than-usual July continued the weather trend for the year.

Analysis of data records kept by the National Institute of Water and Atmospheric Research (Niwa) shows the past month was second only to 2017 for Gisborne’s warmest mean daily maximum for July.

That record, for the average of daily maximum temperatures over the month, stands at 16.7 degrees.

Last month and the Julys of 1991 and 1967 were second-equal on 16.4.

July 2019 was also one of Gisborne’s warmest Julys overall. The mean daily temperature, which is the average of maximums and minimums, was 11 degrees.

Niwa records show the 11-degrees mark has been hit only 10 times in Gisborne since 1937, including six times in the past 12 years, which indicates an accelerating warming trend. It was reached only four times before that.

The all-time warmest July was in 1967 when the month reached a mean temperature of 11.8.

Last month was 2.2 degrees warmer than the 30-year average (1981 to 2010) for July’s mean daily maximum temperature.

It was overall 1.3 degrees warmer than the 30-year average for the whole month.

Contributing to that were clear skies and 166.5 hours of sunshine — 50 hours above the 30-year average and 30 hours more than the MetService running average for July in Gisborne.

Over the month there were only nine wet days of 1mm or more rainfall. These delivered 83mm, or 65 percent of the 30-year average of 128mm.

To date, the year continues to run about 200mm short of normal rainfall.

There were 13 days of north-west winds. An overall 21 days of winds from the drier west and northerly directions helped keep temperatures up.

There were just nine days of colder southerly quarter winds and overnight temperatures were a fraction warmer than usual.

Eight days of ground frost were experienced — about par for July — and the coldest grass minimum was a fairly ordinary minus-4.1 on the 10th.

The lowest grass minimum on record is minus-8.9 set in 1973.

Last month’s warmest day hit 21 degrees on the 14th -— 0.2 of a degree short of the all-time warmest July day for Gisborne in 1964.