Cool, wet August ends fairly average summer

29 08 2014

After a dry and warm start, summer 2014 is set to end on a rather average note – with temperatures and rainfall close to normal levels for the season.

Using figures up to 27 August and then assuming average conditions for the final few days of the month, Met Office statistics show the UK mean temperature for this summer will be around 14.8C. This is just 0.5C above the long term average (1981-2010).

Rainfall overall is close to average, with the UK having seen 246.7mm of rain – which is just over the long-term average of 241.0mm. Rainfall from the final few days of August will add to this number, so overall the summer will be slightly wetter than average.

As ever when looking over a whole season, the statistics mask some big variations between each month.

June and July were both characterised by drier and warmer than average conditions across the UK which meant the summer was already one of the best we’ve seen in recent years.

UK rainfall as a percentage of the long-term (1981-2010) average

Map showing August UK rainfall as a percentage of the long-term (1981-2010) average for the month

August bucked that trend, however, with cooler and wetter than average weather. Taken together, this has led to the fairly average final statistics for summer.

Looking specifically at the early August figures, also released today, the UK mean temperature up to the 27th of the month is 13.8C which is 1.1C below the long-term average. This ranks it as currently the coolest August since 1993, but that could change when the final few days of the month are added.

August is also the first month since November 2013 to have been cooler than average, breaking an eight month run.

In terms of rainfall, August has been much wetter than average, with 127.1mm of rain which is 142% of the long-term average (89.5mm). This makes it the 18th wettest August in the records, but it may climb higher when the figures for the whole month are available.

 

Mean Temperature Rainfall
Summer* Actual (°C)
Diff from Avg Actual (mm)
% of Avg
UK 14.8 0.5 258.2 107
England 15.9 0.4 211.6 109
Wales 14.8 0.3 257.5 90
Scotland 13.1 0.6 338.4 111
N Ireland 14.3 0.4 244.6 96

*Please note these are projected numbers that include statistics from 1 June to 27 August, then assume average conditions for the final few days of the season. They may not accurately represent the final full-season figures.

 

Mean Temperature Sunshine hours Rainfall
August** Actual (°C)
Diff from Avg Actual (hours)
% of Avg Actual (mm)
% of Avg
UK 13.8 -1.1 154.2 95 127.1 142
England 14.9 -1.2 169.7 93 103.4 149
Wales 13.9 -1.0 152.3 91 128.2 119
Scotland 11.9 -1.1 132.4 99 169.0 145
N Ireland 13.3 -1.0 134.2 99 112.8 116

** Please note these are preliminary statistics from 1-27 August. The final figures will change once statistics from the final few days of the month are included.





A wet start to August

15 08 2014

The UK has already seen nearly its entire ‘normal’ rainfall for August in the first half of the month.

Figures up to the 13th of August show there has been 86.1mm of rain so far in the UK, just short of the 89.5mm long-term (1981-2010) average.

Looking at individual countries, Scotland has already seen more than its full-month average with 121.4mm of rain so far compared to the average of 116.7mm. The Inverness and Moray areas have been particularly wet, with significant flooding from ex-hurricane Bertha on 10 to 11 August.

Rainfall for England and Northern Ireland so far is just under the full-month average, while Wales has been the driest relatively speaking – with 83.2mm of rain making up 77% of its full-month average. Normally at this stage you would expect about 42% of the average to have fallen.

With regards to temperatures and sunshine, the month has been much closer to average so far.

The UK mean temperature is currently 15.2C, which is 0.3C above the full-month average.

UK sunshine hours are at 77.8 hours, which is 48% of the full-month average – so just ahead of where we’d expect after 13 days of the month.

While these figures are interesting, they don’t tell us where the month will end up overall – we’ll have to wait until the full-month figures are in before deciding where this August fits in to the records.

As we head in to next week there should be a good deal of drier weather but with northerly winds bringing in cooler air it will feel colder than of late, especially at night.

This will feel noticeably cool in the wind, so people heading out in the evening may want to take a few extra layers.

Mean temperature Sunshine Rainfall
1 – 13 August 2014 Actual

Diff from 81-10 average

Actual % of 81-10 average Actual % of 81-10 average
Celsius Celsius hours % mm %
UK 15.2 0.3 77.8 48 86.1 96
England 16.5 0.4 91.8 50 64.7 93
Wales 15.3 0.3 85.1 51 83.2 77
Scotland 13.2 0.2 55.3 41 121.4 104
N Ireland 14.5 0.2 61.9 46 92.7 95




August weather summary

11 09 2013

Overall August saw quiet weather, with temperatures close to average. Forecaster Helen talks through the weather we saw in August in our summary video.

A maximum temperature of 34.1 °C was recorded at Heathrow on the 1st, the highest UK temperature since July 2006. A minimum temperature of 0.2 °C was recorded at Kinbrace (Sutherland) on the 5th. In the 24 hours ending at 0900 GMT on the 5th, 61.0 mm of rain fell at Porthmadog (Gwynedd). A wind gusts of 68 mph was recorded at Needles Old Battery (Isle of Wight) on the 17th. Visit our climate section for a full written summary of the month.

Your pictures

Thank you for sharing your pictures of August weather with us on Twitter, here’s a few of our favourites…





August Bank Holiday weather extremes

23 08 2013

The August Bank Holiday is always the last Monday in August, although these statistics include Saturday and Sunday, to look at the whole weekend. At this time of year it can still be quite hot, although there have been few instances of this actually being the case over the Bank Holiday weekend itself. In some years the progression of Atlantic low-pressure systems have arrived by the end of August, bringing wind and rain.

Here are the warmest, coldest, wettest and windiest August Bank Holiday weekends, as provided by the Met Office National Climate Information Centre.

Warmest

Temperatures reached 31.6 °C at London Weather Centre on Saturday 25 August 2001, and more than twenty stations exceeded 30 °C on that day, mostly in the south-east and East Anglia. Saturday 25th August 1990 was also very warm in many parts.

Coldest

Numerous Scottish stations failed to get above 10 °C on Sunday 28th August 2011, the lowest maximum being 9.1 °C at Cromdale. This excludes stations 500 metres above sea level, which may be considerably colder.

There have also been numerous instances of air frost over the August Bank Holiday, most of them in Scotland, most notably in 1977 and 1982. The lowest individual reading was -3.1 °C at Kindrogan on Sunday 28 August 1977.

Wettest

On occasions 100 mm or more of rainfall has been recorded in a day. The highest 0900 GMT – 0900 GMT figure is 152.2 mm, recorded at Glendessary on Monday 31 August 1992. Widespread heavy rainfall also came from the remnants of Hurricane Charlie on Monday 25 August 1986.

Windiest

A maximum gust of 78 mph was reported at Lerwick on Monday 29 August 2005. Strong winds were also relatively widespread in 1986 and 1992.

Check your local Bank Holiday weather forecast on our website.





The jet stream and why it’s too early to write-off summer

13 05 2013

There have been one or two stories in the press today saying we’re in for another washout summer, which would rightly inspire collective misery across the country.

However, it’s a far too early to be writing off any chance of a decent summer season – after all, it doesn’t officially start (for us meteorologists) for more than two weeks (on 1 June).

It appears the news stories are borne out of the current position of the jet stream, a band of fast moving westerly winds high up in the atmosphere. But why is this important?

A quick Jet stream explainer

The jet stream tends to guide the generally wet and windy weather systems which come in off the Atlantic. So, if it’s over us or just to the south, we tend to get a lot of wet and windy weather – which is what we expect through winter.

If the jet is to the north of us, it guides that changeable weather to the north to give us more settled conditions – which is what we expect in the summer.

(You can read a bit more about the jet stream, how it impacted our weather last year, and any potential connections to climate change in a blog story we wrote last year).

What’s going on now?

Right now the jet stream is sitting to the south of the country and it is influencing the unsettled weather we are seeing at the moment.

Forecast chart showing position of the jet stream at midday on 13 May 2013

Forecast chart showing position of the jet stream at midday on 13 May 2013

It’s fair to say that this is roughly the position it was in for extended periods during the exceptionally wet weather that we saw last year, particularly in June.

Crucially, however, the jet stream does move around quite a bit and it can change its track significantly in just a few days. So the current position of the jet stream does not mean that it’s stuck in that position.

Looking ahead

Much like our weather, it’s a huge challenge to predict the exact track of the jet stream more than five or six days ahead, so there’s still a great deal to play for in the outlook for our summer.

In short, it’s far too early to write-off summer 2013 based on the current position of the jet stream.

To get the best information on what to expect you can see the latest detailed forecasts out to 5-days on our website, as well as a general view of what we expect out to 30 days.

You can find out more about the jet stream in our YouTube video.





Cold night breaks August records in places

31 08 2012

Last night saw some unusually cold August night-time temperatures across parts of the UK, with some observation sites hitting record lows.

Among those stations seeing their coldest recorded August temperature were:

Braemar No 2, Aberdeenshire: -2.4 °C

Aviemore, Highlands: -1.8 °C

Redesdale Camp, Northumberland: -0.7 °C

Bainbridge, North Yorkshire: 0.5 °C

Benson, Oxfordshire: 2.1 °C

Bradford, West Yorkshire: 2.8 °C

Observation sites have operated for differing amounts of time, so some records are more significant than others. Out of the new records, Bradford has the longest historical dataset – going back to 1908.

It’s worth noting that none of these break the all-time record low UK temperature for August, which is -4.5 °C recorded at Lagganlia, in Inverness-shire on 21 August 1973.

Why was it so cold in places?

Last night saw northerly winds drag cold air from quite a long way north over the UK. This air was also dry, which meant there was very little moisture to help retain heat from the day.

This, combined with clear skies caused by the high pressure sitting over the country, meant all the heat radiated into the sky – leaving very cold temperatures for the time of year.

Once in a blue moon?

While UK weather records such as this aren’t broken once in a blue moon (we’ve had many broken already this year), this set does more or less coincide with the astronomical phenomenon.

A blue moon occurs when there are two full moons in one month – which is perhaps not as rare as the saying may have us believe. There was a full moon at the start of August and now a full moon is due tonight.

You can read more about this in articles online, such as this one at earthsky.org








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