Early spring warmth this year, but sometimes winter can bite back in March or even April

It's turned much milder recently and eastern England has seen a taste of Spring-like warmth today, with southerly winds and sunshine pushing temperatures up into the mid to high teens. Santon Downham in west Suffolk looks like it's recorded the highest temperature today, 18.4C, the highest temperature of the year so far. This just 10 days after temperatures struggled to get above freezing across East Anglia and, indeed, many other parts. With the early spring-like warmth before winter has finished and March, the start of meteorological Spring, less than a week away, it is natural to think winter is now behind us and the weather will progressively get better.

However, in reality, the weather may tease us with early hints of spring warmth, but can flip to bring a cruel reminder of winter in early spring – even well into April.

There’s no such flip back to winter showing in the models for the next 7 days at least. Fortunately the persistent rain affecting the north and far west will be banished by Thursday, as high pressure builds north, bringing drier and more settled conditions for all. Eventually a large area of high pressure looks to settle over the UK over the weekend and high pressure looks to stick close by through early next week too. As high pressure builds north later this week, it will cut off the warm southerly flow, so although it will remain fairly mild by day in the sunshine, nights will turn colder, thanks to subsiding dry air from aloft in the anticyclone drying the air out which allows temperatures to drop lower at night. Why deserts get cold at night under clear skies, thanks to the dry air. Over the weekend we could see frost return overnight and similalry into early next week.

High pressue looks to be close by as head into early March, as the ensemble spread for surface pressure below shows:

So, March will be coming in like a lamb, with the drier and more settled anticyclonic picture as we head into the first few days of March, with pleasantly warm sunshine by day and chilly nights. But, history tells us, there is always the possibility through March and indeed April, of a return of wintry conditions. Though, of course, often winter doesn’t return again until later in the year.

Looking through the records over the years, the return of snow and below freezing nights is not as uncommon in March or even April as you’d think. Below are some of the more notable flips from an early taste of spring back into winter in March or April:

2013 – Most recently, March started dry with mild spring-like days but chilly nights, Trawsgoed, Ceredigon, west Wales reached 17.5C on the 5th. However, from around the 10th, a very cold easterly flow developed sourced from Siberia. Heavy snow fell on the 11th and 12th on the south coast and even Channel Islands, further snow brought disruption to NE England and eastern Scotland mid-month. Between 22nd-24th saw the most significant snowfall, as Atlantic frontal systems bumped into the cold easterly flow, bringing prolonged and heavy snow to north Wales, northern England, SW Scotland and N, Ireland – with 20cm falling widely. Bitter easterly winds continued for the rest of the month. Snow fell on 20 days across parts of the Midlands, northern England and Scotland from the 10th.

2001 – March saw spring arrive in fits and starts. A very cold and snowy start to the month, some low sub-zero maxima in the north, -4.6C at Cassley, Sutherland on the 2nd, then the following morning -21C at Altnaharra on the 3rd.  It then warmed up, with 17C at Cardiff on the 7th, mild spell lasting until mid-month, but just when it seemed like winter was left behind, cold returned from mid-month, as a bitterly cold easterly flow developed. 10cm of snow fell in Powys on the 17th, also significant snow in the south on the 20th, as Atlantic fronts bumped into the cold air.

1989 – After a warm end to March, with Canterbury reaching 20.7C on the 28th, an area of high pressure developed over Scandinavia from April 1st, which ushered in unusually cold air from the east for a few days, with London seeing snow on the 5th, 18cm of snow at Tadworth (Surrey) on the southern edge of London.

1981 – After a wet but mild March, the first half of April was sunny and warm, particularly in the north, Easter was cloudless, but soon after northerly winds set in, sweeping cold arctic air south on the 22nd. There was a maximum of only 1C on the 24th at Leeming (Yorks) and Nottingham. Significant snow fell across the Pennines, Midlands, West Country, central southern and SW England between the 24th and 26th, blizzard conditions across the Pennines with 20’ drifts across the Peak District.

1975 – March you’d expect temperatures to get progressively higher as the month wears on, but not so this year. Highs of 14-15C were recorded in England and Wales during the first week. But, by contrast, the Easter Holiday (28-31) was cold, with showers of snow, sleet or hail. There was snow cover in places during the holiday. Cold northerlies with snow showers continued during the first 10 days of April too, with lying snow in the southeast on the 9th.

1968 – A late March heatwave saw the temperature reach 25.0C at Cromer, Norfolk on the 29th, thanks to southerly winds. However, 4 days later, it was snowing in London and parts of SE England, after a cold front moved south on the 2nd of April, with a low of -10.6C recorded at Achnagiochan (Strathspey) that morning.

Of course, there are mild spring-like ends to winter, that lead into warm springs, with no return of winter, that get progressively warmer day-by-day. 2003 was a good example of this. February was mild, March and April were dry, sunny and warm on the whole – this then lead into a hot summer.