Trevor Wheeler's weather review for 2017

AFTER what had been the driest December since 1988, January tried to redress the balance, but only just, as the 100mm (3.94ins) that fell was only a little more than the average of 90mm (3.54ins).

Cold weather initially, provided a temperature of minus 7.8? (18?) on the morning of the 3rd. A cold spell began on the 12th with rain turning to snow, and again on the 13th snow fell. But amounts on both days were small. This cold snap lasted until the 27th during which time the thermometer fell to minus 9.4? (15?) at the dawn of the 22nd, eventually becoming the lowest reading of the year. This had followed on from the previous day’s maximum temperature of 3? (37.4?), although a few days later, on the 26th a lower daytime maximum was recorded when just 1? (33.8?) was noted. At its conclusion, January finished on a generally mild theme.

After a mild start, February experienced a cold spell during its second week, with snow showers, and yet again a maximum daytime temperature of 1? (33.8?) on the 11th. Gradually temperatures recovered but, at its finale, chilly air was once again evident. Over the course of February, sleet and snow was recorded on six days, while the precipitation total was less than expected. This greatly contributed, with the lack of winter rainfall, to withholding the local aquifers from fully replenishing themselves, and in the process preventing the flow of the local winterbournes in their upper reaches.

March came in like a lion, with stormy conditions, but slowly this situation improved. With the daylight lengthening, and the sun’s strength increasing, temperatures responded, with 16? (61?) achieved on the 26th, the first occasion that 60? plus had occurred for the year. An even better figure was realized on the 30th when 20? (68?) was enjoyed across the district. Many places across southern and eastern England recorded an even higher reading of 22.2? (72?), thus ensuring March went out like a lamb!

Occasionally, greatly influenced by a strong high pressure cell being close to, or over the country, April can be very dry, and during 2017 this was prevalent, as over the whole 12 months, this month became the driest with an extremely low rainfall total of just 5.6mm (0.22ins). Only during the years of 1984, 2007, and 2011 has April recorded smaller totals over a 50-year period.

The one significant factor to occur throughout April though, was a late season frost on the morning of the 27th, the thermometer reading falling to minus 5? (23?). This was the coldest April morning since 1981, which resulted in damage to early tender plants and shrubs, with several spring flowering species being completely scorched across the district.

Overall, May was a showery month, with the first thunderstorm of the year making its presence felt on the 11th. Two others followed during the course of the month, none of them being severe.

Sunshine and temperatures were close to, or just above average, whilst one air frost occurred, which was noted on the morning of the 10th, when minus 2? (28.4?) was recorded. By the end of May, rainfall for the month was less than normal, helping to establish three consecutive seasons which all produced below average precipitation, from the autumn of 2016, followed by the ensuing winter, and then spring.

An unsettled spell of weather heralded the arrival of June, with 260mm (1.02ins) falling on the 5th. This day also witnessed strong winds, while the following day, the 6th, was again affected by high winds, with gusts of 60mph recorded across coastal districts of southern Hampshire.

After this unseasonal start to the month, the weather pattern changed and June became perhaps arguably the best of the summer months, proven by warm, and sometimes hot, sunny days. Temperatures soared into the 30s, with the best of these, and the years highest reading, occurring on the 21st where the mercury touched 33? (91.4?). Some places across the south of England experienced even higher temperatures, especially at Heathrow Airport which recorded 34.5? (94?), the highest June temperature recorded since 1976.

After a promising start to July, with good sunshine, and temperatures reaching the upper 20s, a sudden change occurred on the 10th. signalling spells of rain and a cooler climate. Torrential rain over the 24-hour period of the 11th produced 40.3mm (1.59 ins), almost creating a new rainfall record for the month, as it was just 0.2mm (0.01ins) less than the July record of 40.5 mm, established on the 9th of the month during 2008. Ultimately, this was to become the year’s wettest day.

The unsettled theme continued into August, frustrating farmers in their attempts to harvest the cereals although, fortunately, there was an improvement during the latter stages of the month, which greatly helped. Over the course of the last eight years, August has received a higher than average rainfall total on no fewer than five occasions across the Andover district.

September was typical of an early autumn month, with cool and unsettled weather, interspersed with some pleasant, warm, sunny days. On the night of 12th / 13th the first of the Meteorological Office’s named autumn / winter storms, ‘Aileen’, tracked across the country, producing windy conditions in the Andover area, but insignificant rainfall. Night-time temperatures throughout the month were generally on the mild side, with no air frost recorded.

Perhaps one of the most interesting phenomenon over the course of 2017 occurred during the morning of 16th October, when the sky took on a coppery colour. This had the effect of bathing everything in this colourful hue and even the sun appeared as a red ball. Most parts of southern and eastern England experienced this spectacle, which had been caused by ex-hurricane ‘Ophelia’ moving north just to the west of Ireland. The strong southerly wind in its circulation had picked up Sahara Desert dust and smoke from forest fires in Portugal, and this mix was then carried aloft towards and over France and England, producing this unusual event. Although now only a tropical storm, ‘Ophelia’ was also responsible for extremely high humidity being felt across the south on the day.

One feature that was missing from October, was the absence of frost until the final four days of the month.

Mild weather announced the introduction of November, and continued for a good part of the month, with occasional cold snaps, more notably around the 12th and 13th, and later with the progression of the month, during the final week. Overnight of the 24th / 25th a band of showers moved southeast across the Andover area, which in their mix produced the first fall of sleet and snow for the 2017/18 winter.

With the end of November, the chilly air transferred into December, temperatures remaining close to, or below their seasonal norm for the first three weeks. During this period sleet and snow fell occasionally, but nothing significant, whilst on the 11th temperatures struggled to achieve 2? (35.6?), following an early morning value of minus 7? (19.5?) thus making this the coldest December day since 2012.

With the run up to Christmas, somewhat milder weather showed itself, but only temporary, as very unsettled conditions arrived on Christmas Day. Boxing Day witnessed heavy afternoon rain before turning to snow overnight, the precipitation total for the day being 31.3mm (1.23ins), the highest daily total for December since 2013. This contributed greatly to the December total of 118.8mm (4.68ins), which then became the year’s wettest month.

To summarise, 2017 received 818.1mm (32.2ins) of rainfall, slightly less than the normal 841mm (33.11ins), and, as a consequence, became the third consecutive year to receive less than average rainfall. Although the rainfall total was lower than usual, the number of precipitation days, 231, was well above the average of 214. An absentee during the year was the incidence of thunder, just 7 days against the usual 11. Air frosts occurred on 87 occasions, close to the average of 84 days.

Trevor Wheeler, Hurstbourne Tarrant.