December 2016 summary

December was notable for persistent high pressure – the barometer never dropped below 1013.8hPa, which means that the pressure remained above the global average (1013hPa) throughout the month. We recorded our highest December average pressure of 1026.4hPa, and a new record high pressure reading of 1044.3hPa was reached on the 27th.

High pressure often brings calm and dry weather and blue skies, but in winter it may also mean persistent cloud and fog instead of sunshine. All of those features were present during December. Rainfall was 25.4mm, well under half the average and the lowest December total we have recorded; and the wind run came to 889nm which is about one third of our December average, making this our quietest December on record. While we’re talking about records, we also saw our highest December temperature of 15.6C on the 7th December, and our warmest Christmas day (0600-1800) with an average of 12.8C.

That’s an impressive list of new records for one month, but all the other features associated with winter high pressure were present too, even if they aren’t so easily measured. We had clear skies, gloomy days and a fair helping of fog. There were no gales but plenty of calm spells, and there was little in the way of rain with the total on the wettest day (the 15th) only amounting to 8.2mm.

December got off to a cold start, with the thermometer down to -4.9C early on the 1st. There was high pressure across the UK, and fog which formed overnight never cleared during the day: as a consequence the temperature remained below freezing all day, the first time that has happened here since 2010.

We remained under the influence of high pressure, either over the UK or not far away, for almost the whole month – Atlantic lows only made their presence felt from the 12th to the 15th and again around the 21st, and even then we were only on the edge of lows passing to our north. Scotland wasn’t so lucky, with rain and gales there while it was calm here.

Some figures for 2016:-

  • Rainfall total was 606.6mm, a little below average but nothing exceptional
  • The mean temperature for the year was 11.1C, close to normal
  • The highest temperature was 32.4C in July, a new record for this station, and the lowest was an unremarkable -5.9C in January.
  • February saw new records set for wind speed.

That’s a lot of new records for one year, and quite a few of those in December – 2016 will be a hard act to follow.

This is a record-breaking high pressure system

The southern half of the UK is sitting under an intense high pressure system which brought clear skies overnight and an air frost this morning, with a minimum temperature of -1.4C.

Nothing too remarkable there, you might think, but this morning we have recorded an atmospheric pressure of 1044.0 hPa. That’s a new record for this station – the previous high was 1043.9 hPa on 8 February 2012 – and the trend is still upwards (just).

This system won’t hang around for long, unfortunately, so enjoy the cold, fine weather while you can. Quite a contrast to the balmy temperatures we had on Christmas Day!

Warmest Christmas Day

Today has seen an average daytime (0600-1800) temperature of 12.8C, which makes this the warmest Christmas Day since the station was set up back in 2007. Although this time last year was also very mild, it was Boxing Day that produced an exceptional daytime average of 14.2C – Christmas day last year only managed 11.6C.

So – a Merry and Mild Christmas to all our visitors!

Record December warmth!

After a cold start to this month with the temperature never getting above freezing on the 1st, we now have a new record high temperature for December: as I’m typing this at 1345 the thermometer is reading 15.6C and still rising. That beats the record of 15.4C set in last year’s extraordinarily mild December.

Early December’s cold was caused by cold air from the east: today’s warmth comes on a southerly breeze fresh from the Mediterranean, along with some welcome sunshine. This mild airflow is set to stay with us for a few days yet but it will bring some rain as well, so enjoy it while you can.

A cold and murky start to December

Quite a change in the weather for the first day of December. After clear blue skies for the last few days of November, today has seen fog coming inland from the Bristol Channel and stretching across much of Somerset. The sun was could be seen very briefly through the fog during the morning, but apart from that it has been a day of gloom and sub-zero temperatures. In fact today’s daytime (0600-1800) average was the lowest of the year so far at -2.0C, with a maximum of -0.2C at 1252.

It has been an almost completely calm day too (hence the fog), with a maximum gust of just 2kts at lunchtime: most of the day the windspeed has been zero.

November 2016 summary

Early November was cool but generally dry, with high pressure nearby for much of the time to protect us from Atlantic low pressure systems. The result was generally dry weather with some clear skies, but a chilly north-westerly airstream. Fronts from low pressure systems to our north produced a little rain around the 8th, and again on the 12th when a westerly airstream brought temperatures closer to normal.

A couple of deep low pressure systems moved up the English Channel on the 20th and 21st: storm Angus arrived on the 20th and produced wind and rain here, but had more impact on the south-east where winds topped 60mph. A second slow-moving low produced a long spell of rain on the 21st: because this fell on saturated ground there was some local flooding here, and more serious problems further south. The fronts from that system wrapped around the centre of the low, and returned the following day to produce more rain: these two low pressure systems produced 41mm of rain over three days.

High pressure began to build from the north on the 23rd, this time resulting in a cold north-easterly airstream. Cloud kept night-time temperatures well above freezing for a few days, but as the high pressure moved south the skies cleared. There was wall-to-wall sunshine by day making it feel warmer than it was – daytime temperatures peaked at around 6C. The clear skies at night meant sharp frosts, and a new November record low of -5.7C was recorded overnight on the 29th/30th. The last day of November saw barely a breath of wind, and at lunchtime a column of smoke could be seen rising in a perfectly straight line until it hit the tropopause and spread out like an anvil cloud.

November’s average temperature was a 7.0C, a degree or so below normal and our second-coldest November value (November 2010 was colder). Rainfall came to 95.6mm which is a little above average, and the highest wind gust was 32kts on the 17th.

 

New record low temperature for November

I’ll do a summary of November’s weather in the next day or two, but thought it worth mentioning that the minimum of -5.7C recorded at 0444 today is a new record low for November at this station.

The average temperature overnight (1800-0600) was -1.9C, which isn’t a record-breaker – we had colder nights on the 27th and 28th November 2010 (and we all remember winter that followed). This cold spell has reduced the average temperature for this month to 7.1C at the time of writing, and it looks as if this might be the second coldest November we have recorded here since the station was set up in 2007 – the coldest, of course, was 2010 with 6.5C, and I doubt if we’ll beat that. See the archive for figures.

October 2016 summary

October’s weather was dominated by high pressure systems which kept the Atlantic lows at bay, and consequently it was generally quiet with below-average rainfall and little wind. Temperatures during the first half of October were below normal, but sunshine often offset the chill: conversely there was some unseasonably mild weather at the end of the month, but also a blanket of stubborn cloud. Overall temperatures were about 1C below average.

October began with a low pressure system just to our north, which brought us 8mm of rain on the 1st. After that, though, we recorded no more rain until the 14th: a high pressure system built up over Scandinavia and blocked the progress of Atlantic lows, while drawing in a cool but dry easterly breeze. There was a warm spell on the 4th/5th with highs over 18C, but at night temperatures dropped away sharply so that the average for the first two weeks of the month was a couple of degrees below what we might have expected. There were some clear blue skies to make up for it, though.

The Scandinavian high moved off east on the 14th, allowing a complex low to bring the first rain for two weeks, and a milder westerly airstream. A few days later we came under the influence of high pressure again, as the Azores high pushed up to the west of the UK. This blocked the Atlantic lows once again but this time with high pressure to our west and low to the east, and consequently a cool north-westerly breeze. This spell produced the lowest temperatures of the month, with misty mornings and a low of 0.8C recorded early on the 22nd.

This high moved off on the 23rd and we had another brief visit from Atlantic weather systems, and an occluded front stuck with us all day on the 24th producing 16.8mm of rain. The lows weren’t in charge for long, though, because on the 26th our third high pressure system of the month developed over northern France and grew to cover the south of the UK for the rest of October.

This high pressure system brough warm and humid air from the south, and the result was some very mild temperatures for the end of October, but also a blanket of cloud which broke only occasionally to give brief sunny intervals. The thermometer reached 16.8C in sunshine on the last day of the month, but much of the last week of October was gloomy and still.

The average temperature for October was 11.0C, a little below normal, and rainfall was 37.6mm – about half the October average. There was little in the way of wind, but the average pressure of 1020.9hPa is our second-highest October value.

September 2016 summary

The summer weather continued well into September this year, with an average temperature of 17.4C for the first fortnight beating all of the previous three months. That warmth was often accompanied by uncomfortable humidity on warm continental air, thanks to high pressure over Europe and lows to our north and west, and it was often cloudy as well as warm. There were some uncomfortably muggy nights, with an average of 19.3C on the night of the 13th / 14th being a new September record: the highest temperature of the month was 25.1C on the 7th, but the warmest day (0600-1800) was the 14th with an average of 21.3C.

The warm and humid weather came to an end when cooler air forced its way in from the west in the middle of the month, with thunderstorms at the boundary with the warmer air to the east. We saw only a brief storm here during the morning of the 13th, but distant thunder could be heard for much of the day as storms made their way north from Devon and Dorset.

The second half of September was cooler than the first, but temperatures were still respectable and with high pressure to our south there was more sunshine and a fresher feel to the weather. Atlantic lows brought some rain, particularly towards the end of the month, but they were well to the north of us and we were protected from the gales and heavy rainfall that affected the north of the UK. The month ended with an average temperature of 16.2C, making this the warmest September on record here, and total rainfall of 64.6mm.

August 2016 summary

After an inauspicious start with 23.0mm of rain recorded on the first of the month, August turned out to be warm with some good spells of sunshine and little rain once that first day was over. High pressure dominated, but even so it was quite a breezy month with some brisk south-westerlies. The highest temperatures of the month came on a south-easterly breeze, though, around the 16th-18th and again on the 23rd when the thermometer reached 28.5C. The average temperature for the month was 17.3C making it our warmest August since the station was set up – the previous record-holder was in 2013 with an average of 17.2C. Rainfall came to 55.6mm, but nearly half of that fell on the first day and the rest of the month was fairly dry. Incidentally, we recorded more rain on 1st August than we did in the whole of July.

The low pressure system which brought the rain on the first stayed with us for a few days, bringing a little more rain until the 5th, then high pressure began to build from the south-west. For much of the following fortnight we were on the boundary of high pressure to the south and low to the north: it wasn’t unbroken sunshine, but there was almost no rain between the 6th and the 18th and there were some warm sunny days. Towards the end of that period the high pressure moved off east and, with low pressure to our west, we were in a south-easterly stream of warm and humid air taking temperatures into the mid-20s.

An unseasonably deep low crossed the UK from the 19th to the 21st making this the windiest spell of the month, but thanks to the sheltering effect of Exmoor and Dartmoor rainfall totals here were low. Once that system had moved off across the north sea, high pressure built again – but this high was to our south-east with low pressure in mid-Atlantic, and by the 23rd we were back to that hot and humid continental air. This was the warmest part of the month, with a high of 28.5C on the 23rd.

Over the following days the high moved off east and we came under the influence of Atlantic lows again, with some spectacular thunderstorms to our east and up to Lincolnshire on the 28th (but just a little rain here). Although that brought an end to the high temperatures, the lows also brought a fresher south-westerly airflow and it felt more comfortable, if a little cooler. Bank Holiday Monday was uncharacteristically dry and sunny thanks to a little ridge of high pressure from the south-west, and the 30th was a fine summer’s day as well – but started with thick mist just to remind us that Autumn is coming. August ended with sunshine and showers on the 31st.

Despite an unpromising start in June, the summer of 2016 averaged a respectable 16.7C and a record high of 32.4C in July, and the rainfall total was a modest 135.6mm. It was breezy throughout the season with an unseasonable gale in June, but overall this was a decent summer.

July’s rainfall total beaten already

Today’s persistent rain clocked up 21.4mm at 2230, equalling the rainfall total for the whole of July – and it’s still raining, though it’s easing off now. We can already be sure that August’s rainfall total will be greater than July’s, and the garden did need it.

July 2016 summary

July’s weather split neatly into two halves – the first fortnight or so was cool and cloudy, but it became warmer from the 16th onwards and we saw temperature records broken on the 19th. The warm weather offset the cool start to the month, and the average temperature of 17.2C was about what we would expect for July. Rainfall was low at 21.4mm, making this our driest July since the station was set up. It was also our windiest July on record, with a stiff south-westerly breeze for much of the month.

Atlantic low pressure systems dominated the first two weeks of July, bringing a good deal of cloud and only a couple of sunny days. As we got to the middle of the middle of the month it looked as if it might be a contender for the coolest July ever, but high pressure over northern France pushed those lows north from the 15th onwards and the weather began to warm up as the skies cleared. On the 17th much of the UK was basking in sunshine, but the sea is still cool and a sea mist developed in the Bristol Channel and moved inland during the afternoon, making it cold and damp here. It wasn’t until the following morning that the mist burned off, and we got our first proper taste of summer on the 18th.

The high moved off to our east on the 19th, and combined with a low pressure system over the Atlantic to draw continental air over the UK in a hot south-easterly breeze. We recorded a new record high temperature of 32.4C during the afternoon, and average daytime and nightime temperature reached new highs as well.

The high pressure moved off over eastern Europe on the 20th and the procession of Atlantic lows took over again, with a warm and rather humid airflow for the rest of the month keeping temperatures about normal and bringing some frontal rain during the last week.

Warmest day on record

As mentioned earlier, today has seen a new record high temperature for this station – the peak was 32.4C at 1518.

The average daytime (0600-1800) temperature today was 26.9C (corrected 20/6/16 – not 27C, as I reported yesterday), which is also a new record for us – so, whichever way you look at it, today has been our warmest day (and tonight looks likely to be our warmest night* as well!).

  • Updated 0920 20/7/16
  • It was indeed a new record for the warmest night (1800-0600) – an uncomfortable average of 23.9C.

A new temperature record

There it is – at 1309 the thermometer reached 31.4C, a new record for this station. It’s still rising, and although the rate of increase is slowing the warmest part of the day is usually later than this. Keep checking back to see how high we go!

This is going to be a warm one.

At 1223 today the temperature here reached 30C, and it’s still rising. At this time yesterday we hadn’t reached 25C.

In fact, the highest temperature recorded here before 1300 on any day was 29.3C on 18 July 2013, and we beat that by a full 1C at 1230 today. The chances are looking good that we’ll beat our all-time record of 31.2C, recorded on 19 July 2013.