Most extreme mild Jan-Mar periods

[Summer8906]

Was wondering which years (particularly in recent times, say post-war) had the most extreme mild Jan-Mar periods.

It seems to be the case that disruption to spring flowering is triggered by prolonged mild weather in Jan-Mar more than any other time of year.

Three stand out in my memory: 1990, 2007 and 2020 - but wondering whether these three are in fact well ahead of any other recent year.

I actually can't remember the effect on spring flowering in 1990 and 2007 very clearly, though I do have one or two isolated memories: many dandelions out by mid-March 1990 (around 3 or 4 weeks early) rhododendrons out at the end of April 1990 (a couple of weeks earlier than normal, but not dramatically earlier) and May 2007 being rather spartan for May, with most of the usual flowers gone - not helped by the dull, cool, unsettled weather, this was a very poor May aesthetically.

April 1990 did have frost and cold outbreaks at times, which may have knocked things back a bit by the end of the month.

Wonder also if anyone has any memories on the effects on spring flowering on any extremely mild starts to the year, i.e. was the second half of spring indeed relatively barren?

Edited January 24 by Summer8906

[Squally77]

  @Summer8906  I distinctly remember 1990 being exceptionally early for Spring flowering and budburst of trees and shrubs. I was 12 at the time and remember Hawthorn bushes coming into leaf in mid February that year, over a month earlier than normal! 2017 was also an exceptionally early Spring also, 2011 after the record warm April, the trees and plants appeared as they would have done in late June or early July. There was damaging frosts in early April 1990 which caused a lot of damage to fruit crops etc.

 

[damianslaw]

2020 from memory brought early spring growth on the back of a very mild winter, likewise 2017 and 2014.

This year we are seeing early growth as well. Crocus has appeared, much earlier than last year. 

1990 was exceptionally mild, likewise 1989, expect those years delivered early growth. Other early spring growth seasons, 1999, 2000, 2007, 2008.

Edited January 24 by damianslaw

[Harry233]

January 2017-March 2017 was a very mild spell of weather from memory. It was mildest winter locally for me on record and probably locally for around 80 years. I only one brief cold snap around the 14th-16th January. February 2017 had a very springlike day on the 20th. Maximum of 14.C and very sunny, I remember a lot of the flowers were in full bloom by the end of February even though it was quite wet and dull. March was very pleasant for much of the month as well and it did have a couple of very warm days towards the end of the month.

[SqueakheartLW]

6 hours ago, Harry233 said:

January 2017-March 2017 was a very mild spell of weather from memory. It was mildest winter locally for me on record and probably locally for around 80 years. I only one brief cold snap around the 14th-16th January. February 2017 had a very springlike day on the 20th. Maximum of 14.C and very sunny, I remember a lot of the flowers were in full bloom by the end of February even though it was quite wet and dull. March was very pleasant for much of the month as well and it did have a couple of very warm days towards the end of the month.

Winter 2016/17 was unusual in that the mildest weather was in Scotland and N Ireland whilst England and Wales were closer to average with some colder than average weather in January in the south. All caused by a semi persistent Sceuro high setup that kept Scotland and N Ireland in SW winds off the Atlantic whilst England and Wales were closer to the high and on occasions got a colder continental feed in January especially.

[BruenSryan]

Here's the mildest January-March periods for the UK mean since records began in 1884.

[Summer8906]

  @Harry233 I forgot about 2017 though I do remember Feb and March having a lot of mild, if rather dull weather. Probably the colder weather in Jan led me not to focus on it.

I do remember everything was early, but not as ridiculously early as 2016 (by Feb) or 2020.

[Summer8906]

  @damianslaw things here don't yet seem silly-early. Little sign of crocuses just yet, and behind 2016 and 2020, doesn't seem too different to normal just yet.

I presume here the cold spell was colder than elsewhere relative to normal, as often happens in anticyclonic weather in winter, where the winds are E-ly in the south and W-ly in the north. Sounds like we had some very hard frosts here.

I guess what happens in mid-Feb will determine whether this is another silly-early year or just a little early.

Hoping there is a break from the mildness before too long as I don't want an overly-early end to spring.

  @BruenSryan Thanks, looks like 2020 was less mild than I perceived it, being way down the list. However I do remember 2020 in recent years did bring one of the most extreme early flowering, beaten only by 2016.

The March 2020 CET was surprisingly low, presumably cold nights dragging it down as I perceived the month as downright warm at times. An amazing statistic that March 2023 was marginally warmer than 2020, showing how ridiculously mild the nights of March 2023 must have been as there were just about zero genuinely warm days.

Edited January 27 by Summer8906

[Harry233]

  @Summer8906 winter 2015/16 wasn’t actually overly mild for myself other than December it was warmer than average but winter 2006/07, 2007/08, 2011/12, 2013/14 were all milder. In fact December 2016 was actually milder than 2015. January 2016 was near average for me and it was actually quite a snowy month although it often got milder and melted quickly so it didn’t last too long. February 2016 was slightly colder than average and had many frosty nights. 2020 is a good one as well. January 2020 was the mildest for me since 2007, February was only slightly milder than average. I think 2017 was more notable because it wasn’t overly wet other than February. January was very dry and March was also quite dry and sunny so it made more pleasant mild weather.

[Harry233]

  @SqueakheartLW 2016/17 was definitely the mildest winter I can think of and it’s the only winter I can think of that had absolutely no days of lying snow. There was a few flurries on a few days but that was it. Only for a few days in January there was a cold snap. February had a brief easterly cold snap around the 10th for a couple of days and aside from that it was mild and wet. 

[Summer8906]

  @Harry233 Interesting to hear about 2017 being so mild further north. Here it didn't seem overly mild due to a somewhat-cold January, with an anticyclone over the country but the south being on its southern side, thus avoiding the westerlies. By contrast 2015/16 was silly mild in Dec, very mild IIRC in Jan and rather mild in Feb, and the earliness of flowering was quite ridiculous! March was cold though, as shown by the absence of 2016 in the table above. I wonder if March was the coldest month of the "winter" in 15/16?

Edited January 28 by Summer8906

[BruenSryan]

If it helps for your use case scenario, here's the mildest January-March periods on record specifically for central southern England and SE England region rather than the UK mean which may have lots of variation.

2016 here had 5.5C (Jan 5.6C, Feb 5.2C, Mar 5.8C).

[damianslaw]

I think the crocus i'm seeing is a winter flower same as snowdrop as they are quite profuse.

[Harry233]

  @Summer8906 It was definitely a very mild winter for us. December 2015 was indeed very mild for us too but we did have a brief snowy period between the 1st-3rd and then a cold snap between the 12th-15th so that did help bring the average down slightly. January 2016 was near average for me and February was slightly colder than average and had many frosts. March 2016 was average for temperatures for me but it was very dry. I do remember it ending on a very cold and windy spell though with some snow showers. Like I said before I think winter 2017 sticks out especially is because it’s the only winter I have ever recorded and seen without any lying snow which for my local area is really unusual, I only live 30 miles away from the Cairngorms and usually my town is one of the worst hit in the country.

[baddie]

I should count 2022, at least for daytime temperatures. January was slightly milder than average, February was very mild and most of March was warm