During May, intense Highs frequented the New Zealand region, in between some very deep Lows spawned out of the north Tasman Sea. The Highs favoured southern New Zealand, overall, resulting in a drier than usual May over the lower half of the South Island. The Lows produced several heavy rain events for the North Island and upper South Island. The most notable occurred on 11-12 May, (the remnants of Cyclone Donna), and 16-18 May. The first week of May was extremely cold, and temperatures lingered on 'fairly ordinary' after that. A significant cold outbreak on 19/20 May produced the first decent snowfall of the year.
May 2017 Climate Anomaly Maps ℅ NIWA.gif
Some very preliminary May 2017 figures for the main centres:
the last 5 days were like 2 to 3c above average here which meant we ended up being 0.2C below normal only here despite the cold snap in the middle of the month
NIWA's May summary is "partly" up - the links to full report and main centre summary are not working. Perhaps they're in the middle of it all at present ...
Nev wrote:I see Dunedin recorded its highest ever May sunshine, Queenstown its second highest and Blenheim its third highest.
Just for the record, May's national average temp of 10.5C was 0.3C below normal.
And the month's highest temp of 23.4C was recorded at Waione on the 10th, while the lowest temp of -6.9C was recorded at Middlemarch on the 22nd.
Only the Blenheim one sounds convincing - the Queenstown value is from a site with much better exposure and the advantage of electronic measurement, and the Musselburgh readings have also increased post-manual. The 1951 reading of 144 hours for Dunedin would probably have translated to a higher electronic reading.
If the oldest Blenheim site is included, its readings of 220 hours in 1930 & 1931 are highest, and 2017 about 5th highest.