A climate scientist says last month was New Zealand's warmest July on the books, going by a measure that took in more than the official number of stations.
Niwa is shortly due to release the official statistics for July, which its meteorologist Ben Noll last week said was on track to finish somewhere in the top five.
New Zealand's warmest July ever recorded, at 1.8C above average, came in 1998 – just as that year's devastating El Nino climate system was dissipating.
Toward the end of last month, the official July temperature record was tracking at about 1.5C above average.
Niwa used the benchmark, long-running seven station series – but Professor Jim Salinger, who helped create that programme, has looked at the picture using 22 land stations.