HAD not another topic dominated our news, April’s weather would have been attracting more media attention. As it is, it’s probably fair to say that the lengthy fine spell made ’lockdown’ slightly more bearable than it might otherwise have been.

With a continuation of the anticyclonic conditions of late March, April began with a hoar frost on the grass. A light breeze from the north-east kept the day cool, despite plenty of sunshine. April 3 saw things start to warm up with the wind coming first from the west, and then from the south on April 5, a very sunny day with the temperature nearing 18C (64F) in Wellington. That night came our first rainfall for more than a fortnight, but it amounted to less than 4mm.

From April 6-16, which included the Easter weekend, we enjoyed an extraordinary spell of weather. Days were largely – if not totally – sunny, temperatures soaring far above the seasonal normal. Five days in succession, in April, with maxima of 21C (70F) or above was for us unprecedented. A maximum of nearly 24C (75F) in Wellington on both April 9 and 10 was astonishing, while the reading of 25.3C (77.5F) on Easter Saturday, April 11, would not have been believed had other sites in the region not reported higher values. To put it in context, the previous earliest date with a temperature of 25C in this area was May 2 (in a notable heatwave in 1990).

Things cooled abruptly on April 13, with a brisk easterly breeze which then eased off to allow a slight frost under a perfectly clear night sky. The next day could not have been sunnier, but was still cool and followed by a night frost, but a brief incursion of warm continental air on April 16 helped the temperature up to near 22C (72F) again. Associated thundery conditions over France then sent a belt of rain slowly northwards, to arrive here very early on April 17 and deposit some 12mm in the Wellington rain gauge. Very welcome rain, that was.

After two very uncharacteristic cool, grey days, strong sunshine reappeared on Sunday April 19 and we began another improbably fine spell of weather. Although not as hot as earlier, we had five days in a row with maxima in the range 20-23C. The week ending Sunday April 26 was blessed by some 80 hours of sunshine, highly unusual even in midsummer. Not surprisingly, by this time the amount of blossom and foliage around made it feel like the middle of May.

Finally, the weather changed. For the last four days of the month, slow-moving low pressure systems sent a series of rain-bearing fronts across our region. With temperatures below average it was at times unpleasant, but it certainly did the garden a lot of good.

Overall, April 2020 was a highly improbable month, with nine days when the temperature in Wellington exceeded 21C (70F) – an unbeatable record? The mean temperature of 11.5C (52.7F) was almost three degrees above normal, making it the equal-second warmest April ever, with 2007, while 2011 holds on to the top spot. And it was the sunniest April on record, the total rainfall of 39mm (1.5 inches) in Wellington being only 56 per cent of the average.

SIMON RATSEY

WWN Weather Correspondent