April 2017 summary

April was the driest month since we started recording here in September 2007, with a rainfall total of just 11.8mm. The previous record holder was May 2010 with 12.4mm.

Records on this site start the weather day at midnight, but traditional Met Office rain gauges are usually read at 0900 (so observers don’t have to scrabble around in the dark) and this means that any rain falling between midnight and 0900 “belongs” to the previous day. Normally this makes little difference over a month, but this morning we recorded 10.0mm of rain between midnight and 0900. If we were using the traditional Met Office weather day, starting an 0900, April’s rain total would almost double to 19.4mm (not 21.8mm, because 2.4mm of April’s rain would belong to March). It would also mean April would have been the 8th-driest month we have recorded, and not a new record holder. All this tells us is that Mother Nature is no respecter of calendars, clocks or statistics.

Rain fell on seven days during the month, and only three of those exceeded 1.0mm. The dry weather was a consequence of persistent high pressure which kept Atlantic lows at bay for most of the month, and brought some welcome sunshine too.

It wasn’t all plain sailing – there were some dull spells when cloud was trapped under the high pressure, and lows did put in an appearance on the 1st, the 25th and of course right at the end of the month on the 30th – hence all that overnight rain. We managed a respectable maximum temperature of 21.1C at lunchtime on the 9th only to see the thermometer plunge during the aftenoon as we switched to cool polar air: a feature which also took the edge off temperatures later in the month, and produced just a few April showers as cold air met warm.

Despite the clear skies there were no hard frosts, with a minimum of 0.0C recorded early on the 27th. The average temperature for April was 9.8C, about normal for this time of year.

Updated 2000 1 May 2017: after a couple of convective showers this afternoon (and some distant thunder), today’s rainfall total has reached 11.8mm. That’s nothing exceptional, but it does mean we have recorded as much rain today as we did in the whole of April.

First rain for a fortnight

This morning we recorded the first rain for over a fortnight, with 0.2mm falling between 0800 and 1000. That isn’t going to keep the garden going for long, nor does it add much to this April’s total – just 4.6mm at the time of typing, and we’re two-thirds of the way through the month. With high pressure never far away humidity has been low too, so the ground has dried out and gardeners are having to provide their own April showers.

I checked to see whether we have seen other months when the first 20 days have been so dry, and there are two – September 2007 (2.8mm at this point in the month), and July 2013 (0.6mm). Both of those months ended with totals in the mid-20s, but the record-holder is May 2010 when we recorded just 12.4mm of rain for the whole month.

There’s plenty of time for things to change before the end of April, but forecasts suggest it will remain dry for a while yet. That May 2010 record could be beaten this month.

March 2017 summary

This Spring is off to a warm start, with an average temperature for March of 9.1C – about 2C above normal, and the warmest March we have recorded since the station was set up in 2007. The previous record holder was March 2012 which averaged 8.7C.

There was no dominant feature of March’s weather, with Atlantic lows and high pressure systems both in evidence at various times during the month. Low pressure was in charge for the first week so we had a run of showers and some breezy days, notably on the 5th when a rapidly-developing low over the midlands produced a 40kt gust during the afternoon. The following day was much quieter with the UK in a col, but a low pressure system over the Bay of Biscay brought 120mph winds to Brittany.

High pressure arrived to our south on the 9th to bring some pleasant Spring sunshine once morning mist had cleared, but it was short-lived and the Atlantic lows were back on the 11th. Although this meant a good deal of cloud, we were in a warm airstream with above-average temperatures for mid-March.

A second high pressure system arrived to the south of the UK on the 15th bringing another settled spell, but again it moved off quite quickly and we were soon back to breezy and showery weather with 12mm of rain overnight on the 21st/22nd. The only air frost of the month was during a clear spell early on the 23rd, but it was short-lived and the temperature only fell to -0.3C – the highest March minimum we have seen.

The third high pressure system of the month formed over the UK late on the 23rd, and with the centre of the high to our north we were in a dry and chilly north-easterly breeze – which rather took the edge off the warmth from the sunshine.

This high moved off east on the 28th, and March ended with a complex series of low pressure systems bringing very mild air up from the south Atlantic, with a temperature of 18.4C recorded on the 30th.

Rainfall came to 49.2mm which is close to average, so the only exceptional feature of March was the warmth – not just from the sunny spells but also the warm southerly airstreams.

February 2017 summary

February was a mild and breezy month, with rainfall about average.

The month started with a procession of Atlantic lows, including a deep one which passed across northern France on the 3rd. There were wind warnings for the UK, but in the event all we saw was some heavy rain and gusty winds during the early evening – nothing out of the ordinary for February. The 5th and 6th brought the first two frosts of the month, but only just with the thermometer less than a degree below zero.

A ridge from the Azores high brought a quiet spell on the 8th with clear skies, and another air frost early on the 9th produced the lowest temperature of the month at -1.6C – quite modest for February. This was also the last air frost of the month – there were only three, and we might expect double that number in February.

The ridge soon receded, to be replaced on the 10th with high pressure over Scandinavia. This meant that some low pressure system passed south of us, initially resulting in a gentle but very cold and dry easterly breeze. The high pressure moved slowly south-west, and as it did so it drew warmer air up from the south: by the 18th daytime temperatures were into double figures.

On the 19th the high pressure moved off east and for the rest of February it was back to the Atlantic lows, including Doris on the 23rd – this system brought our highest wind speeds of the month (30kts gusting to 43kts), but it was the north of the UK which was most affected. The month ended with a good deal of unsettled weather, with hail and sleet on the 27th.

The average temperature for February was 6.8C, about a degree above normal thanks to that warm spell in the middle of the month, and total rainfall was about average at 57.6mm.

Today is the first day of meteorological spring, and the average temperature for winter 2016/17 was 6.1C, and the rainfall total was 139.8mm – both figures close to normal.