Is another UK heatwave coming in September? Met Office says Hurricane Larry unlikely to bring hot weather
After a sunny start to September many of us will be hoping for the late summer sun to continue.
So will another heatwave arrive on our shores?
Here’s everything you need to know.
What is a heatwave?
According to the Met Office a UK heatwave is when somewhere records at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.
The temperature threshold is different depending on where you are in the country.
Will there be a heatwave?
There had been reports that Hurricane Larry, in the Atlantic Ocean, would result in a mini-heatwave here in the UK, but no, there is no heatwave forecast at the moment.
Stephen Dixon, spokesperson at the Met Office, said: “It may not be the news you wanted to hear but in short there’s not a heatwave in the forecast at the moment.
“The influence of ex-hurricane Larry is fairly limited from here on. Although there is a chance of some higher pressure later this week, it is not currently set to be heatwave conditions by the Met Office’s standard.
“Larry’s influence over the weather has finished as far as we are concerned. It had led to some uncertainty in the forecast at the end of last week, but it underwent a transition in north Atlantic Friday, and with how Larry developed over the weekend we are more confident about how the weather will be in the UK this week.”
But this doesn’t mean things are going to be awful, and many places in the south will see temperatures at or above 20C, from Wednesday to Friday, while they will hover in the late teens elsewhere.
The Met Office says Tuesday will see areas of rain merging over south and central parts then moving northwards. Perhaps some very heavy rain here. Mostly light rain elsewhere. Becoming closer in south.
Wednesday and Thursday will see rain and drizzle erratically clear from eastern England on Wednesday. Generally fine conditions then prevailing until late Friday, when cloud, strengthening winds, and some heavy rain arrive across western areas.
Late summer sun would be welcomed by many (Photo: Finnbarr Webster/Getty)
What is the Met Office long range forecast?
Friday 17 September – 26 September
Fine and dry to start across central and eastern areas on Friday. Outbreaks of rain, heavy in places, and strong winds across the northwest at first will gradually spread southeastwards through the day.
Through the weekend and beyond, there is a signal for mostly fine and dry weather across southern and eastern areas, with variable amounts of cloud and sunny spells, but with the risk of overnight fog patches.
Towards the northwest, perhaps cloudier with the chance of rain at times, which may spread south-eastwards to other areas. There is also the possibility that these unsettled conditions may become more widespread across the UK.
Overall, temperatures are likely to be near to above average, but with the chance of some cool nights particularly in the north.
When will the heatwave end? How long September’s hot UK weather will last and latest Met Office forecast
Monday 27 September – Monday 11 October
Confidence is fairly low through this period. However, the current signals suggest low pressure will lie to the northwest of the UK. This may bring unsettled conditions to northwestern areas, with a low risk of stormy conditions at times. In the southeast more settled weather is likely.
Towards the end of October, a trend towards more widely settled conditions is possible. Overall, rainfall is expected to be above average with temperatures warmer than average.
What about other forecasts?
The BBC’s weather forecast says:
Saturday 11 September to Sunday 19 September
Mostly unsettled weather with a brief dry spell
“For the weekend and first part of the new week, UK weather will be dominated by weak areas of low pressure drifting slowly in from the southwest. These will keep things cloudy and bring bands of rain to many areas, heavy in some places. Temperatures running a bit above average across the country. A brief dry spell is then likely around midweek as high pressure moves east across northern Europe. Towards the weekend, fronts and low pressure should bring some wetter, windier weather for all and cooler Atlantic air.”
Monday 20 September to Sunday 26 September
Weather fronts keeping it changeable but warm
“The final full week of September has seen some changes in recent updates, but confidence is increasing as we see a better consensus among our computer models. High pressure is most likely to build in East Europe and Scandinavia as well as linger in the sub-tropical Atlantic to our southwest. This will open the door for low pressure near Iceland, the aptly named “Icelandic Low”, to displace nearer to the UK. An unsettled and rather changeable pattern is expected to continue throughout the week, with weather fronts bringing spells of rain and cooler days while occasional ridges of high pressure mix things up with some dry, sunny breaks.
“Temperatures will tend to fluctuate day-to-day but hover just above average. This is because low pressure systems will slow down as they approach Europe, thanks to high pressure to the east. As they slow, warmer southwest winds will feed some sub-tropical Atlantic air into the UK. There will be cooler spells behind cold fronts as the North Atlantic air moves in from the northwest.
The alternative scenario is for a strong high pressure system to build overhead, either extending into the UK from the east or building in from the southwest. This would be a dry, largely sunny, and warm pattern as southerly winds bring air from Spain and France. Support for this pattern is waning, but there is still perhaps a 25 per cent chance.”
Netweather’s long range forecast says:
Monday 20 September – Sunday 26 September
“This period looks set to have high pressure dominate over Scandinavia with low pressure over Iceland, resulting in southerly winds blowing frequently over the British Isles, albeit generally not pulling air masses up from very far south.
“As a result, temperatures during this week will generally be on the warm side, though not exceptionally so. Rain belts will periodically push in from the North Atlantic, but will tend to make limited progress into north-eastern areas. However, they are likely to be persistent and heavy at times in western Scotland and in the west of Northern Ireland, and will slide eastwards across the south and especially south-west of England and Wales at times.
For much of eastern Britain, the weather will be mostly dry and settled, with variable amounts of cloud, but the east and especially south-east of England will tend to be predominantly sunny. Late in the week, the low pressure may start to make more inroads from the west, bringing wetter weather further east especially through England, but confidence in this is quite low. Some thundery outbreaks are possible chiefly in the south-west.
“Mean temperatures are forecast to be above the 1981-2010 long-term normal, by around 2C in central and eastern Scotland and in the north of England, but nearer 1C above in the south of Britain and in Northern Ireland.
“Rainfall totals are forecast to be near normal in Northern Ireland, western Scotland, much of Wales and in south-west England. Elsewhere, they will generally be below normal, especially in eastern coastal regions from East Anglia northwards.
“Sunshine totals are forecast to be below normal in Northern Ireland and in Wales and south-west England, but above normal in most eastern parts of the UK. East Anglia will probably see the largest positive sunshine anomalies.”
Week 3: Monday 27 September – Sunday 3 October
“Confidence reduces during this period but it looks like the Scandinavian blocking high will hold firm during the early part of this period at least, but with low pressure over Iceland nudging a little further east, introducing a changeable south to south-westerly type for the British Isles.
Thus, temperatures will continue above normal, though generally not exceptionally so, with rain belts moving in from the North Atlantic more frequently and moving more freely from south-west to north-east. That said, the rain belts will probably become lighter and patchier as they head into sheltered north-eastern areas. In the brighter interludes in between the rain belts, there may be some heavy and locally thundery showers in the west and south.
Later in the week, we may see winds switch to a west to south-westerly with high pressure building in the south, giving a more traditional northwest-southeast split in the weather, with drier, sunnier weather towards the south-east.
“Mean temperatures are expected to show similar anomalies to the previous week, with much of Scotland and northern England coming out about 2C above average, but southern Britain and Northern Ireland nearer 1C above. Rainfall totals are expected to be mostly above normal except in eastern Scotland and north-east England. Sunshine totals will probably be below average in the west and above average in the east and also above average in northern Scotland.”