2005 was another very warm year at Durham, 6th highest on record since 1850, another in a sequence of very warm years that have made the last 10 years the warmest ‘decade’ on record at Durham. It was drier than normal, but not notably so.
January was a mild month with all measures of temperature well above average. Mean air temperature for January was 9th highest since 1850, the warmest since 1989. It was a dry month, with rainfall total well below average, continuing the pattern of the previous two months – the 3-month total is well below average therefore. Perhaps most notable was the wind – it was generally a very windy month, with mean speeds well above average. Extremely high gusts on the morning of the 8th caused havoc on the A1 and brought down a large chimney at St Cuthbert’s Society on the Durham peninsula. The maximum gust of 137km/h (86mph) is the highest recorded since the new anemometer was installed in 1999.
Despite feeling rather cold at times, February was, overall, a mild month, well above the long-term average and ranking 101st in a series of 156 years. Perhaps a run of very mild winters has made us overly sensitive to colder months, imagining them to be more extreme than is the case; in fact, one only has to go back to 2003 to find a much colder February! Rainfall was, once again, below average and all three long-term cumulative totals fell below average at this time. Sunshine was close to average, although there were only two days in the month with no bright sunshine at all. For the winter as whole, it was both very mild and very dry. It was the 10th warmest winter on record since 1850, although 0.2°C cooler than in 2004. Perhaps more unusually, it was one of the driest winters on record, 11th driest since 1853 and the driest since 1973. Five of the ten driest winters were experienced in the 19th Century, when summers tended to be much wetter than winters; in recent decades, winters have tended to be wetter than summers, so a winter as dry as this one is now something of a rarity.
March was another mild month, with maximum temperatures well above average and minimum temperatures even more so (the highest mean minimum for March since 1997). Overall, mean air temperature was the same as last year and the highest since 1998 (equal 19th highest since records began). There were 12 ground frosts and 7 air frosts, but all in the first half of the month. Rainfall was just below average, a dry month generally but with 20mm on the 27th raising the total to near average. It was a dull month too, with sunshine hours well below average, the 10th dullest March since 1882 and the worst since 1996. There were 9 days recorded with no bright sunshine, again the lowest number since 1996. There was a particularly gloomy end to the month over the Easter weekend which was both wet and sunless.
Mean air temperature in April was above average, but this masked a contrast between mean daily maximum – a little below average – and mean daily minimum – well above average. This suggests a relatively cloudy month – certainly sunshine was only a little above average and it was, overall, a wet month. In fact, there were only 10 rain days, and the large total was accounted for by two very wet days – 14th and 15th when a total of 58.8mm fell, a notably large two-day total for Durham. The 3-month and 12-month rainfall totals were now back to average levels but the 6-month total remained well below average, reflecting the dry winter.
Although of above-average temperature, May was nevertheless somewhat disappointing, the coolest since 1997. That the warmest day was on the 3rd and the sunniest day was on the 12th suggest that the expected heat and sun towards the end of the month did not materialise. It was, however, a dry month: exactly the same total as a year ago but both Mays being only the driest since 2001. There was a notable gust on the afternoon of Saturday 28th of 87km/h. With an average of 8.4°C. spring ranks = 19th highest with 1949 and 2000. Of the other years this decade, only 2001 has had a cooler spring; 2003, 2004 and 2002 rank 1st, 3rd and 4th respectively.
June started in a very disappointing manner, with some very cool days, including a maximum on the 6th of only 12.4°C and one of 12.8°C on the 7th. However, the second half of the month was notably warm and so, overall, the month ended up above average, more so because of warm nights than warm days. The maximum of 26.7°C on the 20th was very welcome indeed. It was only the coolest June since 2002, however, so again memories (of a below-par June in this case) proved short! Perhaps the most notable event was the downpour on the early evening of Sunday 19th. Though less dramatic than elsewhere in the region, it was nevertheless exceptional, with 21mm falling in an hour (18:00 – 19:00 BST), most of that in about 40 minutes, accompanied by thunder and lightning. There was localised flooding in Durham City, including in Hatfield College where the chaplain’s valedictory sermon was accompanied by thunder and lightning! June was less sunny than May, and just below average.
July was warmer than average, but not exceptionally so, lying just within the interquartile range, 117th in a series of 156. Minimum temperatures were well above average, more so than maximum temperatures, reflecting the relatively cloudy and wet month. Total sunshine was just below average and total rainfall was above average. The 5th, 6th and especially the 28th were wet days. In between there were some warm days, with daily maxima exceeding 20° from the 9th to the 19th. One must go back to 1968 to find a July with more days without any bright sunshine at all. In all, therefore, July was a somewhat mixed month but at least with some warm, sunny summer weather in the middle of the month.
August was a little above average temperature, but not greatly so. It was a dry month, with only just over half the normal amount of rainfall. By now, all long-period totals had fallen below average, the 12-month total significantly so. [By contrast, August 2004 was a very wet month indeed.] Sunshine was above average but the running total for the year remained well below average. It should be mentioned here that the automatic weather station at the Observatory failed to operate after a power cut on the 14th. This fault was not discovered until 7th September. Mean temperatures for August and September were therefore interpolated from maps on the Met Office website; daily rainfall figures are based on the Environment Agency record from Barker’s Haugh Sewage Treatment Works in Durham City.
Summer was drier than normal (148mm against an average of 182mm) but still considerably wetter than the preceding winter (75mm). The 1990s were characterised by winters being wetter than summers, but this pattern has reversed in the 2000s. The winter:summer ratio was 0.51 in 2005, the 23rd lowest on record since 1852. As noted above, summers tended to be wetter than winters in the 19th Century and of the 22 lower ratio values, 12 date from the period between 1852 and 1900. At 15.1°C, the summer of 2005 ranks equal 17th with 2001 and 2002. 2004 ranks = 11th and 2003 1st, indicating just how warm summers at Durham since this decade have been.
The (estimated) mean air temperature of 14.1°C for September makes it one of the warmest on record at Durham since 1850. It ranks 8th highest on record, the highest since 1999 (which ranks 3rd). Unusually, apart form 1999, none of the other very warm Septembers have been recent: three years from the 1890s and two from the 1940s rank above September 2005, plus 1865. The warmest September at Durham was in 1949 (15.3°C). September was a little wetter than average. The wettest day was the 8th with 15.2mm with 30mm on the 7th and 8th combined. Despite the rainfall, sunshine was a little above average too, with the cumulative sunshine total approaching the average figure for the first time since January.
October was a mild, wet month, typically autumnal except perhaps for being less windy than normal. All measures of temperature were well above average. Mean daily maximum was the 5th highest on record since 1950 while mean daily minimum was the 2nd highest on record since1950. Overall, mean air temperature was the 3rd warmest on record since 1850, beaten only by 1969 and the record holder, 2001, which was a whole degree Celsius warmer than October 2005. October rainfall was well above average, though not exceptional by any means. Not surprisingly, sunshine was below average. The wettest day was the 13th with 13mm, but 12.8mm on the 12th must also be noted, falling in a very short time and causing localised flooding.
November was a cool month by recent standards, still a little above the 1961-90 average, but nevertheless the coolest since 1998. It was, in many ways, a more traditional November, some colder air mixed in with the milder westerlies. An indication of the variable weather was that, in addition to 16 ground frosts, there were also 16 rain days. It was mild at the beginning of the month, but very cold later on. The daytime maximum on the 23rd was only 2°C! The changeable weather was also reflected in the rainfall: wet at the beginning and very end of the month, but dry during the cold period. The three – and six-month totals rose above average for the first time in several months (since April and January respectively), but the 12-month total remained well below average (where it had been since August). Sunshine was above average; indeed there were more hours of bright sunshine than in October. This brought the cumulative sunshine total for 2005 almost back to the average level. There was a notable gust on the afternoon of the 11th which was a very windy day indeed: 107.4km/h [58kt] from a southerly direction. Autumn rainfall (211mm) was a little above average (44th wettest in a series of 156). In contrast, the April-October rainfall total (298mm) was a little below average (333mm), reflecting drier months in late spring and summer. In terms of temperature, autumn 2005 ranks = 5th at 10.7°C; 2001 lies 1st with 11.1°C. The warmest 30 autumns include 10 since since 1990; as with other seasons, recent warming is clear to see in the Durham record.
Like November, December was a mixed month: some very mild days in the middle but extremely cold after Christmas. The absolute minimum of -9°C on the 29th was the coldest day in Durham since 4th March 2001 and the lowest December temperature for a decade. The temperature only reached -0.7°C on the 7th. Overall, December was above average temperature, mainly because daytime temperatures were well above average, night-time temperatures being only marginally so. It ranks 99th warmest in a series of 156 years, but was the coolest this decade. December was a dry month, with only 61% of the normal amount. Sunshine was a little over average, but it was a calm month, with mean wind speed well below average.
Overall, 2005 was a warm year, 1.1°C above average. Every single month of the year was above the 1961-1990 average. 2005 was the 6th highest on record since 1850, although the coolest since 2001. For the record, the warmest years on record at Durham (to two decimal places) are now:
2005 – 9.71
1990 – 9.75
2002 – 9.80
1949 – 9.83
2003 – 9.88
2004 – 9.96
Only 1990 and 1949 have rivalled the last four years therefore. The extraordinary warmth of the last few years is reflected in the fact that, if we take the average of every 10-year period (1850-59, 1851-60, etc.), then the last decade (1996-2005) is the warmest on record and the first to average 9.5°C. As it happens, the coldest ‘decade’ on record at Durham is 1879-1888 (7.7°C); an increase of just over 1°C in a little over a century does not sound much, but is in fact a huge increase compared the ‘historical’ record. Moreover, an increase of 1.1°C has occurred since the 1960s, a remarkable rate of warming. The mean maximum temperature for 2005 was 8th highest since 1950, while the mean minimum was 3rd highest. 2005 was a dry year, but not remarkably so, only 112th driest in 154 years, and some 40mm wetter than the rather drier 2003. Sunshine hours ended up just above average, having lagged behind for most of the year. It was a little windier than normal, but in this regard the most remarkable event was the damaging winds on 8th January.
Professor Tim Burt
Department of Geography