Irish Weather Statistics

I promised I would give you guys an article on June 1887 if I found enough data, to celebrate the 130th anniversary of Ireland's warmest day on record, 26th June 1887. And here you guys go, I give you my article on said event. Hope y'all enjoy it and find it informative!

I would like you guys to know that this article was very challenging and difficult to make due to the lack of data there is available. Thank you very much to all the sources I name in the article as without these sources, I would not be able to make the article. I'm just the "presenter" or "writer" for the article so I'm the least important you could say in all of this.

June 1-3: The first few days of June 1887 were rather mild but nothing exciting with daytime temperatures slightly above average for early June around the 15-17c range. The odd place got up to 18-20c in the sunshine. High pressure was to the north of Europe up to Greenland and building to the north and east of Ireland with a trough to the south bringing the winds in from an easterly to a southeasterly direction. The trough was very weak in nature so any rain that did fall was very light. It was quite a north-south split with some very sunny spells in the north and much cloudier in the south.





June 4-7: The trough starts pushing away to the east of Europe on the 4th. The ridge of high pressure builds to the east of the country and over the UK with an area of low pressure to the west of Ireland forcing the winds to come from a southerly. It became very warm in some places during this period as a result. The +10c isotherm got quite close to Britain on the 6th and actually makes in roads to Britain on the 7th which would bring daytime temperatures easily into the mid 20s whilst much of Ireland would be in the high teens to low 20s. With the exception of the west of Ireland close to the area of low pressure, there was plenty of sunshine associated with the ridge of high pressure making it feel much much warmer than what it actually was.





June 8-12: After a slow start to the period with the low pressure from the Atlantic successfully making in roads to the north of Ireland as well as Scotland, the ridge of high pressure from the south starts building across the whole of the UK and Ireland bringing very settled and fine conditions. Temperatures would be in the 17-20c range each day. However, with the high UV levels of sunlight, it would feel much warmer. These were the least interesting days of June 1887 as you can probably tell given the amount of information to share here and talk about but nevertheless, the days were still very pleasant with the sunshine and fine temperatures.





June 13-30: An intense anticyclone ridged in across Ireland for the rest of June with plentiful warm, dry and sunny weather persisting. Temperatures gradually started rising as June went on. The odd station or two recorded some showers on the 14th and 16th but these stations and showers were very, very localised and isolated. At the start of the period, maximum temperatures were frequently reaching 20-24c. Around the second week of the period - and third week of June 1887 overall, they started reaching the 24-27c mark. By the last weekend of June, temperatures had risen into the low 30s in many places which was very abnormal for Ireland, never mind being abnormal for June. On June 26th, Kilkenny recorded Ireland's all-time maximum temperature with 33.3c in very sunny conditions. As a result of this phenomenal Irish maximum temperature, Ireland had a higher maximum for 1887 than the UK. There is no other year in history where Ireland recorded a higher maximum than the UK. This maximum temperature has not been beaten since. However, there have been two very close contenders with 32.5c at Boora, Co. Offaly on 26th June 1976 and 32.3c at Elphin, Co. Roscommon on 19th July 2006. This was a remarkably dry, hot and sunny period again especially for Ireland, never mind the fact that it happened in June, normally the coolest month of the meteorological Summer in Ireland. For the remaining days of June, temperatures dropped a little but were still well above normal in the low to mid 20s widely.





I would like to thank mickmackey1 for sharing this article from the Dublin Daily Express:



You can find the original post to it here. Give him a thanks while you're at it!: http://www.boards.ie/vbulletin/showpost.php?p=100399214&postcount=1216

I would like to thank pedigree 6 for sharing this interesting document: http://www.cso.ie/en/media/csoie/releasespublications/documents/agriculture/farmingsincethefamine/General_Details_-_Farming_Since_the_Famine.pdf

Here is the part where it speaks about June 1887:

January was about average as to rainfall and temperature, the number of rainy days being slightly below the average. February was very dry and slightly colder than usual. March had a deficient rainfall and was decidedly cold. April was very dry and the coldest April since 1860, with the exception of April 1879. May was dry and rather cold. Then came a great change. On Sunday, June 5th, the temperature rose and for the remainder of the month we had a combination of heat and drought, which lasted until July 10th. No record exists of such a hot and dry June in the south and south-east of Ireland. For thirty-four consecutive days a blazing sun shone like a fire-ball in the cloudless sky. Not a drop of rain fell, except a sprinkle on one day. It was at the period of the year when the nights were shortest and the sun was at its maximum altitude; there was little dew. After the cold, dry spring, vegetation was backward and all thought it would be a late harvest. The ground was parched at the commencement and the herbage stunted by cold wind. Then came the period of fierce heat and the sun played on the pastures, the corn and the young turnips; the grass was burned brown; the corn, stimulated by high temperature and sunshine, shot prematurely into ear, at a height of six inches and though the harvest was expected to be late on June 1st, the fields were turning yellow in the second week in July. The succulent and tender young turnips were shrivelled and scorched and if a few survived, they quickly succumbed to the fly and the Aphis, or plant louse.

You can find the original post to it here and don't forget to give him a thanks also: http://www.boards.ie/vbulletin/showpost.php?p=103861719&postcount=671

To finish it all off, here is the reanalysis for June 1887 from NOAA. The reanalysis shows a ridge of high pressure extending from Greenland all the way down to Morocco with an area of low pressure to the east of Scandinavia into Russia. As a result, the jet stream is on a very northerly track which brings the winds up from a southerly or southeasterly direction bringing in those very warm days during June 1887 and Ireland's warmest day on record. That is a very good chart for a Summer month if you want hot and dry weather. The CET (Central England Temperature) for June 1887 was 15.3c which is +1.0c above the average from 1659-2012. June 2016 was a very humid and muggy month as you all know and the CET for that month was 15.2c which meant that June 1887 was +0.1c warmer than June 2016. Unfortunately, daily data available online for Irish stations does not go back to as far as June 1887 so I cannot calculate the IMT (Irish Mean Temperature) for June 1887. If I were to estimate, I think the IMT would be around 15.6c which is +1.9c above the 1981-2010 average. Blackrock, Co. Cork recorded a mean temperature of 17.4c for June 1887 which was +3.2c above its average for June. Dublin's mean temperature for June 1887 was 16.8c which was +2.6c above its average for June. June 1887 was one of Dublin's warmest months on record at the time. Dublin also recorded 21c or more on at least 17 days during June 1887. Despite June 1976 (Ireland's current warmest June on record) being warmer than June 1887, I think that June 1887 was more interesting, in my opinion. This goes to show you how warm June 1887 was. With this setup and from the summary, it's no surprise that June 1887 was a very dry month. Here are examples of rainfall totals for June 1887 to show you how dry it was:

Fitzwilliam Square, Co. Dublin: 6.4mm
Ballinasloe, Co. Galway: 10.7mm
Omagh, Co. Tyrone: 16.3mm
Waringstown, Co. Down: 19.3mm
Browne's Hill, Co. Carlow: 6.6mm
Blackrock, Co. Cork: 13.5mm

Read more rainfall totals for June 1887 here in Symon's Meteorological Magazine for July 1887: https://digital.nmla.metoffice.gov.uk/download/file/sdb%3AdigitalFile%7Cd32a6d77-3f7c-402f-96b4-2d6291a6306f/

The same magazine also states the length of the absolute drought (14 days or more with 0mm of rainfall) that took place across Ireland during June 1887. For example, from June 8th-30th 1887, Dublin recorded no rainfall and that was 23 days without any rain! Here's more examples of the length of the absolute drought during June 1887 in places:

Navan, Co. Meath: 6th-30th (25 days)
Browne's Hill, Co. Carlow: 10th-30th (21 days)
Gorey, Co. Wexford: 8th-30th (23 days)
Athlone, Co. Westmeath: 9th-30th (22 days)
Fermoy, Co. Cork: 8th-30th (23 days)

Read the magazine in the link above for more examples.

Elmer Blooker wrote: »

Good work sryan, you put some time and effort into that and historical weather is right up my alley!

But one nitpick - surely 850hpa temperatures were much higher than 10c on June 26th 1887, meteorology would have been quite primitive then so the chart you posted would not be entirely accurate in my opinion.
Heres a chart from July 1983 (the forgotten summer!) when the temperature exceeded 31c for five consecutive days at Kilkenny. What a chart!!

Hi Elmer,

The chart of 850hPa temperatures could be inaccurate but also accurate. 850hPa temperatures do not show the full story or picture which is why I said it could be accurate also. It could be quite warm in the upper air but down on the surface, temperatures can be much cooler or vice versa. This was the case with September 1988. Here on 8 September 1988 in the chart below, you can see the +20c isotherm pushing into the UK. Normally, an isotherm like this would bring temperatures in around the low 30s. However, the maximum temperature of September 1988 was only 26.9c on the preceding day, the 7th. This was very disappointing and shocking for an isotherm such as this. Compare this with the chart you just named. However, I'm not arguing with you saying that the chart is inaccurate as it could be either judging from this.



As for Summer 1983 being forgotten by many people, I have to disagree. I think that Summer 1995 and 1976 overshadow 1983 yes but the forgotten Summer I find is Summer 1989 which was equally as good if you ask me - July 1989 was even hotter than July 1983 (at least with the IMT - the CET for July 1983 is higher than July 1989) but people tend to remember July 1983 more? But yes, that is a beautiful chart, have to agree with you there.

The provisional IMT for June 2017 is 14.7c.

Oneiric 3 wrote: »

Works out at around 0.7c above the 1961-90 average, with the above average mean for the month holding more on the strength of the mean minima, which was over a degree above average, nationally speaking. Rainfall in excess of 150% also over the country as a whole.

This would make it one of the warmest Junes on record in terms of mean minima. I'm not sure where it would rank but it would definitely be in the top 10 or even top 5 by the looks of things. June 2016 currently ranks as the warmest for mean minimum temperatures. June 2016 an IMT of 15.0c.

Here's many of the Winter forecasting methodology all mixed into two tables for the winters 1950/51 to 2016/17. I hope some of you will find use for these tables as they were extremely tedious for me to make. All data was from NOAA, UKMO, Silso and this graph for the OPI: http://kaltwetter.com/der-winter-201415-kommt-opi-endergebnis-uebertrifft-alle-erwartungen/. The OPI for October 2015 & 2016 are not confirmed, they are only estimates by myself as there is no data available for them Octobers.

This is the mean sea level pressure for the day when the Titanic set off on its final journey (11 April 1912). Again courtesy of Deep Easterly which in turn was courtesy of NOAA.



Find the original post here: http://www.boards.ie/vbulletin/showthread.php?p=78067258

This chart is of the 7 day running IMT anomaly for Spring 2016 up to May 3rd. Courtesy of you Oneiric 3 & Met Éireann.

These are the December 2015 rainfall totals for some Irish stations as courtesy of Oneiric 3 & Met Éireann.

sryanbruen wrote: »

Provisional IMT for July 2017 was 14.9c, Ireland's first colder than normal month since November 2016.

Confirmed at 14.9c.

As Meteorite58 brought it up, I thought I'd take the courtesy in doing a historical post on the 5 August 1986 deluge here in Ireland.

Here's what Met reann say about this event:

On the morning of Tuesday 5th, however, a vigorous depression approached from the southwest and moved northeastwards, preceded by active rainbelts.

The heaviest rain from this weather system was in the very moist air from lower latitudes ahead of the depression centre. Again the south was the worst area affected. The rain began in earnest in Cahirciveen, Co. Kerry, around noon and continued without respite till after midnight. There were 7 consecutive hours of continuous heavy rain (heavy rain is defined as rain falling at a rate of 6mm an hour or more). A total of 85.6mm fell there that day, which is not far short of the station's normal rainfall for the whole month of August. 56mm of that total fell in the 6 hours between 1 and 7 o'clock. New records were set for 6 and 12 hour falls of rain.

As the rainfall map across shows, Kerry and west Cork were hardest hit. An underground river overflowed in Tralee and flooded part of the town. In Bantry, the town centre was under 3 feet of water. Macroom, Skibereen, Millstreet and Bandon were among the many other towns in the area also flooded that day. Many roads in the region were affected and a number of bridges were swept away. Other parts of the country were hit too, with flooding in Ennis, Co. Clare, Cappamore, Co. Limerick, and as far north as Co. Sligo.

The table across shows some of the rainfall amounts measured on the 5th.
Totals such as these, which are fairly typical of the amounts recorded throughout the southwest on the 5th, would be expected not more than once every 50 years, on average. Elsewhere in the country, 24 hour rainfall totals ranged from 30-50mm. The rain was driven by strong winds gusting up to 50 knots in the southwest.

Information from this source: http://www.met.ie/climate-ireland/weather-events/Aug1986_HurCharlie.pdf

As can be seen from the 850hPa temperatures chart below, warm air was pushing against pretty cool air over Ireland on 5 August 1986. The stark contrast between the two created this very vicious Summer storm or deluge.

When was Spring sunnier than the Summer for the UK? All of the following years (seems to have become much more common within the past decade). There is no average sunshine totals currently for Ireland as a whole unlike the UK thus why I can only show the UK - if I can, I might calculate the ISTs in future (Irish Sunshine Totals) like I am currently with the IMTs going back further than the 1980s.

2016 Spring: 487.7 hours | Summer: 474.7 hours
2015 Spring: 509.3 hours | Summer: 499.2 hours
2012 Spring: 477.8 hours | Summer: 402.7 hours
2011 Spring: 516.1 hours | Summer: 472.8 hours
2010 Spring: 499.8 hours | Summer: 494.8 hours
2008 Spring: 473.6 hours | Summer: 451.4 hours
2007 Spring: 521.3 hours | Summer: 473.0 hours
2002 Spring: 454.6 hours | Summer: 439.0 hours
1987 Spring: 415.8 hours | Summer: 401.9 hours
1982 Spring: 496.2 hours | Summer: 463.3 hours
1980 Spring: 464.3 hours | Summer: 395.8 hours
1958 Spring: 422.8 hours | Summer: 416.3 hours
1956 Spring: 504.8 hours | Summer: 456.0 hours
1954 Spring: 432.8 hours | Summer: 376.8 hours
1953 Spring: 491.6 hours | Summer: 479.8 hours
1948 Spring: 557.5 hours | Summer: 425.9 hours
1946 Spring: 479.4 hours | Summer: 459.2 hours
1942 Spring: 484.0 hours | Summer: 465.5 hours
1929 Spring: 534.2 hours | Summer: 525.0 hours

Information from: http://www.metoffice.gov.uk/pub/data/weather/uk/climate/datasets/Sunshine/date/UK.txt

sryanbruen wrote: »

The provisional IMT for August 2017 stands at only 14.3c which would be -1.1c below the 1981-2010 average.

Slight miscalculation with the final IMT for August 2017 at 14.2c.

September maybe regarded by the people as one of the quietest months of the year within the past two decades but it was not always quiet and settled. For example, September 1961, 56 years ago,:

Ireland was hit by winds gusting over 110m.p.h. as the centre of the former hurricane Debbie passed close to the west coast during the morning of Saturday, September 16th 1961. At a number of stations the winds recorded that day were the highest measured either before or since, while the gust of 98 knots (113m.p.h.) at Malin Head is the joint highest gust ever recorded in Ireland - the same value was recorded at Foynes, Co. Limerick on January 18th 1945, before the instrument pen went off the chart. While true hurricanes are technically not found at latitudes as high as Ireland, Debbie retained many hurricane characteristics when it arrived off the southwest coast. Damage to property was extensive over the western half of the country and 11 deaths were attributed to the storm. Debbie was unusual in developing into a hurricane so far east in the Atlantic. It reached category 1 status on the Saffir-Simpson scale on the 6th, just off the Cape Verde Islands (see chart below) where it caused a plane crash and the deaths of 60 people. After reaching category 3 status in mid-Atlantic on the 11th, with mean windspeeds of over 100 knots (120m.p.h.), it turned northeastwards towards Ireland and lost some of its intensity over the cooler waters of the North Atlantic. Debbie moved on to cause severe gales over Scotland, while the remains of the storm could be traced as far east as Russia towards the end of the month.





Original source: http://www.met.ie/climate-ireland/weather-events/Sep1961_hurricane-Debbie.pdf

September confirmed at 12.7c.

Seems that a cooldown has definitely taken place since July as you can see from the IMTs and their anomalies.

January: 6.1c (+0.6c)
February: 6.4c (+1.1c)
March: 8.3c (+1.2c)
April: 8.8c (+0.3c)
May: 12.9c (+1.6c) - though this is a figure open up to question
June: 14.7c (+1.0c)
July: 14.9c (-0.5c)
August: 14.2c (-1.2c)
September: 12.7c (-0.3c)

Some things to note:

- June was warmer than August
- September was not nearly as cold as 2012 or 2015 despite what people say
- Spring was the warmest since 2011

Like I said, this was being worked on before my June 1887 article, so some of the information at the start of the post might be out of date :P.

sryanbruen wrote: »

September maybe regarded by the people as one of the quietest months of the year within the past two decades but it was not always quiet and settled. For example, September 1961, 56 years ago,:

Ireland was hit by winds gusting over 110m.p.h. as the centre of the former hurricane Debbie passed close to the west coast during the morning of Saturday, September 16th 1961. At a number of stations the winds recorded that day were the highest measured either before or since, while the gust of 98 knots (113m.p.h.) at Malin Head is the joint highest gust ever recorded in Ireland - the same value was recorded at Foynes, Co. Limerick on January 18th 1945, before the instrument pen went off the chart. While true hurricanes are technically not found at latitudes as high as Ireland, Debbie retained many hurricane characteristics when it arrived off the southwest coast. Damage to property was extensive over the western half of the country and 11 deaths were attributed to the storm. Debbie was unusual in developing into a hurricane so far east in the Atlantic. It reached category 1 status on the Saffir-Simpson scale on the 6th, just off the Cape Verde Islands (see chart below) where it caused a plane crash and the deaths of 60 people. After reaching category 3 status in mid-Atlantic on the 11th, with mean windspeeds of over 100 knots (120m.p.h.), it turned northeastwards towards Ireland and lost some of its intensity over the cooler waters of the North Atlantic. Debbie moved on to cause severe gales over Scotland, while the remains of the storm could be traced as far east as Russia towards the end of the month.





Original source: http://www.met.ie/climate-ireland/weather-events/Sep1961_hurricane-Debbie.pdf

Who'd have known we'd have something similar to this nearly a month later after me posting about it? :P

For anybody interested, here's some of the maximum wind gusts recorded as a result of Ophelia from yesterday, Monday, October 16th.



Source: http://www.met.ie/latest/yesterday.asp