The wettest year at Durham since records began in 1850.
Following on from the warmest year on record, January continued in the same vein, the warmest since 2008 (2007 was even warmer) and as such, much more typical of winter conditions experienced in the early 2000s than the last three winters. It was the 29th equal warmest January since 1850, so just into the top 20%. The beginning of the month was remarkably mild with no air frost until the 13th. It was another dry month; the 3, 6 and 12-month rainfall totals were all now below average. It was the third sunniest January on record since 1882, although less sunny than 2007 (94.1 hours).
February was another mild month, although rather cooler than in 2011. Overall, it was the 33rd equal warmest February at Durham since 1850. It was very much a month of two halves: cold at the start, remarkably mild towards the end. The daily maximum temperature remained marginally below zero on the 4th and was less than 1°C on the 9th and 10th. By contrast, the maximum of 17.4°C on the 28th was the warmest ever February day in Durham since records begin. The previous record was 16.8°C, set in 1993. Durham was apparently the warmest place in the UK that day – the Pennines producing its very own “chinook” effect! In complete contrast, the absolute minimum on the night of the 8th was the lowest February temperature at Durham since 1994; the grass minimum the same night was the lowest since 1991. February was also a very dry month, although only the driest since 2008; it was the 15th lowest February total since 1850. Sunshine was also above average, the sunniest February since 2009.
For the Winter as a whole, this was the mildest (average 4.8°C) since 2007 and the 12th equal warmest on record. It was 33rd driest (98mm) winter on record, the lowest winter total since 2006. It was also the 3rd sunniest winter on record (238.6 hours), beaten only in 2000 and 2007.
March was the second warmest on record at Durham since 1850 (8.4°C); only March 1938 has been warmer (9.2°C). The mean daily maximum temperature was the warmest for March (records from 1900), the figure of 13.7°C easily beating the 1930 value of 13.1°C. Mean minimum temperatures were less remarkable, although still well above average, 17th equal highest since 1900. The absolute maximum was 0.1°C higher than that recorded in 1965 but available records only go back to 1962 so this may not be a record. Notwithstanding the high temperatures, there was still an above-average number of ground frosts (17), but only three air frosts. It was the 4th sunniest March since 1882, and the highest total since 2003. March was also a very dry month, 21st driest since 1850, the driest March at Durham since 2003. The 3-month total was the 39th lowest for any consecutive 3 months since 1850 (n = 1945) and the 6-month (72nd lowest) and 12-month (222nd lowest) running totals were also well below average, if not quite so extreme. It is driest start to a calendar year at Durham since 1973 and the 8th driest start since 1850. So, at the end of March, Durham was just like the rest of Eastern England in suffering from a developing drought, with growing anxiety about possible water shortages during the summer – how wrong we were!
Mean air temperature in April was below average but not greatly so, the 62nd equal coolest April at Durham since 1850. It was the contrast with March that made it seem so disappointing. There have been 21 years since 1850 when March has been warmer than April (roughly one in eight years therefore). This year has seen the 2nd largest difference (1.7°C); only 1938 had a bigger difference between a warmer March and colder April (1.9°C). It was a very wet April but not the record total, unlike locations further south: Oxford, for example, saw the wettest April on record since 1767. This was only the 3rd highest total at Durham since 1850, exceeded relatively recently in 1998 (151.0mm) and 2000 (150.0mm). Whilst the 3-month total was now back to normal, the 6-month total remained well below average. The 26th was the wettest day at Durham (25.6mm) since 6th August 2011. It was also a very disappointing month for sunshine, the 7th lowest April total since 1882 but only the dullest April since 2004. As with mean air temperature, March was much sunnier, over 90 extra hours of bright sunshine in March despite the shorter day length. Nevertheless, the cumulative total of bright sunshine to the end of April remained well above average.
May was a month of “thirds” – two thirds cold and one third hot! The early part of the month was disappointing, including 6 days when the maximum stayed below 10°C. However, the maximum exceeded 20°C each day between the 22nd and the 29th, with an absolute maximum on 25.2°C on the 28th – the 4th highest absolute maximum for the month of May since 1962. Overall, May was above average for mean air temperature but not noticeably so, (some) warmer days being offset by cool nights. Rainfall was above average but the 6-month total still remained below normal. There was less bright sunshine than usual for May. This was the 9th year since 1882 when the number of hours of bright sunshine in March exceeded that for May; the last time this happened was in 2003.
June was an extremely poor month in all respects! Daytime temperatures were particularly disappointing. The mean maximum temperature was well below normal, the lowest since 1997. Night-time temperatures were only a little less than usual, but still the lowest since 1999. The resulting mean air temperature was therefore well below average, the lowest since 1991 and 32nd equal lowest since 1850, easily in the lowest quartile. The absolute maximum (21.5°C) was the lowest since 2002. Like April, June was another very wet month: the third wettest June on record at Durham since 1850, exceeded only by 1997 (177.4mm) and 1980 (191.4mm). The three-month total (April to June inclusive) was the 12th highest total for any three months since 1850 (n = 1948) and the highest since May – July 1980. There were daily totals above 20mm on the 8th (21.2mm), 15th (20.6mm) and 28th (27.4mm). A very intense storm on the relatively warm afternoon of the 28th produced hourly totals of 13.6mm (1600 – 1659) and 5mm (1700 – 1759). Probably the storm lasted no longer than about 30 minutes (we have no means of tracking anything other than hourly totals); the estimated intensity was certainly “noteworthy” therefore (Salter, The Rainfall of the British Isles, 1921). It was easily the dullest June on record at Durham since 1882, well below the previous worst, 1987. There were 3 hours less bright sunshine per day than in a normal June, and only the 20th saw more than 10 hours bright sunshine.
July 2012 had exactly the same mean air temperature as July 2011, another disappointing below-average month, the second in a row. Days were cooler but nights warmer than a year ago. There were only 9 days when the air temperature went above 20°C. For the 4th month in a row, rainfall was well above average. Indeed, those four months were the 3rd wettest of any consecutive 4 months since records began (435.4mm), beaten only by November 1978 to February 1979 (453.7mm) and in 1867 (May – August: 503mm). In just 4 months, Durham had gone from a major deficit to a large excess! As with June, July was another very poor month for sunshine, well below average; it was the 5th lowest total for any July since 1882 and the worst since 1968.
August had above-average temperatures but not greatly so, ranking 121st in 163 years. Days were rather more above average than nights: 17 of the first 21 days exceeded 20°C but the maximum was only 23.5°C (14th). Thereafter it was cooler and the maximum on the 30th was only 13.8°C. Rainfall was well above average, 136th wettest since 1850. This simply added to an already exceptionally wet late spring and summer: Durham experienced the 37th wettest 5-month period since 1850 (n = 1947). August was sunnier than June or July but May and even March were both sunnier. Only 6 days in August had more than 6 hours sunshine.
The Summer as a whole was 0.2°C below average mean air temperature, ranking only 72nd out of 163. It was the 2nd wettest summer on record (340mm), but well beaten by 1867 (390.6mm) which must have been very disappointing indeed! It was a very dull summer, the second dullest summer at Durham since records began in 1882 (268.5 hours) but still considerably sunnier than 1912 when the total was only 223 hours.
It was the coolest September in Durham since 1994. The mean maximum was only the lowest since 2008 but the mean minimum was the lowest since 1994 (equal to 1997). And yet, the warmest day of the year (maximum 25.8°C) was on the 7th! There were no air or ground frosts. There was exceptionally heavy rainfall and flooding towards the end of the month. The rainfall was spread across two days, with 47.4mm recorded on the 24th and 40.8mm on the 25th. The former is the 27th wettest day on record at Durham since 1850 and the latter was the 41st wettest. Looking at 2-day totals, the combined total of 88.2mm is the 5th highest 2-day total since 1850, although well less than the record holder, 10th / 11th September 1976 when a total of 120.1mm was recorded. The heaviest rain fell late on the evening of the 24th when 16mm fell in 3 hours. It was the wettest September since 1976 and the 7th wettest on record. Notwithstanding the large amount of rainfall, sunshine in September was just above average; the number of rain days (11) was just below average (14). Of all possible 6-month periods (n = 1948), the period from April to September was the wettest ever. Of all possible 12-month periods, the “year” to the end of September ranked 21st wettest out of 1952 such periods. For the 3-month period, this was the 67th wettest in a total of 1943. In relation to the autumn period specifically, this was the 4th wettest, beaten only in 1976, 1944 and most recently in 2000.
October was a cold month: the mean air temperature was the equal 28th coldest since 1850 and the coldest since 1993. Mean maximum was equal 30th lowest since 1900, the coolest since 1993. The mean minimum was more extreme: 9th lowest since 1900 and the lowest since 1992. The absolute maximum was disappointing at only 16.1°C, again the lowest since 1993. There was the highest number of ground frosts since 1981. It was the wettest October since 2004 with the most rain days since 2006. As might be expected, the long-period totals remained very extreme: the 32nd wettest of any 3-month period since 1850; the 2nd wettest 6-month period, only exceeded by the previous 6 months (i.e. April – September 2012); and the 38th wettest of any 12-month period (n = 1943). Not surprisingly, it was the wettest 7-month period in Durham since records began. By the end of October, the total for 2012 was already 808.8mm – already the 8th wettest year on record even if we got no rain at all in November or December! However, just like April, June and September, November was another extraordinary month for rainfall, three days in particular. The total of 49.4mm on 26th was the 24th largest daily total since 1850; the 2-day total (25th + 26th) was the 21st highest 2-day total on record whilst the 3-day total (25th – 27th) was 13th highest 3-day total on record. It rained for 11 hours on the 25th, for 19 hours on the 27th and, remarkably, rainfall was recorded in each and every hour on the 26th. The maximum hourly intensity was 4.6mm (11.00 – 12.00a.m., 26th), part of a total of 15.6mm during the period 9 a.m. to 1 p.m. on the 26th. It was the 12th wettest November since 1850. The 6-month total (June – November inclusive) was the highest total for any 6-month period since 1850 making it incidentally the wettest summer and autumn on record. This was only the second time that a 6-month total has exceeded the mean annual rainfall total at Durham, the other occasion being the 6-month total to the end of September. The 3-month (autumn) total was the 17th highest on record, whilst the 12-month total (i.e. December 2011 to November 2012 inclusive) was the 4th highest on record, beaten only in 2001 and 1872 (twice). Hardly surprisingly, the 8-month total (since April) was the highest on record for any 8-month period at Durham, beating the previous record form 1853. By the end of November it was already the wettest year on record at Durham! Meanwhile, average temperature in November was a little above average, sunshine too.
In December therefore, all the focus was on rainfall: would another above-average month lead to a calendar-year total at Durham over 1000mm (40 inches) for the first time since records began in 1850? The answer was “yes”, with the total of 99.8mm more than enough to reach 1033mm for the year. It was the wettest December since 1978, the 16th wettest since 1850. Of course, all the long-period totals stayed well above average: it was the 36th highest of any 3-month total, the 3rd highest 6-month total (only beaten by two other 3-month totals in 2012) and the wettest ever 12-month period (beating the previous record, the 12 months up to and including February 2001, the only other time a 12-month total has exceeded 1000mm at Durham, 1005.8mm). Not surprisingly, it was also the highest 9-month period on record, easily the wettest ever “end” to a calendar year. Recalling that the 3-month total to the end of March 2012 was the 39th lowest for any consecutive 3 months since 1850, the last three-quarters of 2013 were truly remarkable in terms of rainfall totals, from near-record drought to record deluge! Mean air temperature was exactly average for December. It was less mild than last year but warmer than 2009 and 2010. There was a relatively high number of ground frosts (22) but a relatively small number of air frosts (9), mostly in the first half of the month. Despite all the rain, sunshine hours were above average, the sunniest December since 2004 (equal to 2006).
In summary, as noted at some length above, this was easily the wettest year on record at Durham since records began in 1850. The total of 1033mm is remarkable, more than 100mm larger than the previous record in 1872 (914.9mm). In statistical terms, the probability of an annual total this large is something less than I in 10,000 – so perhaps the wettest year since the last Ice Age! Curiously there were 4 fewer rain days (183) than normal. In terms of temperature, it was above average (8.92°C), ranking 127th out of 163 years. Not surprisingly, it was disappointing year for sunshine, ranking only 34th since 1882, yet there were slightly more ground frosts than normal. However, the main memory will be of a remarkably wet end to a year that started with a winter drought!
Professor Tim Burt
Department of Geography