An exceptionally warm year, 2nd warmest on record at Durham since records began in 1850, and a wet year too.
Following a cool December (2001), January was mild, 26th warmest on record, though less warm than January 2000. Daytime temperatures were in particular above average. It was drier than normal, although not notably so, ranking 48th in a series of 151. Nevertheless, sunshine was only about average for the time of year. There were exceptional gales on the 28th with a maximum gust of 67kt (124km/hr) on the afternoon of the 28th; the high winds caused major disruptions locally on the A1 with a number of lorries being blown over.
February was also a very mild month, the 5th equal warmest since 1850, exceeded only by 1903, 1990, 1945 and 1998 (by far the warmest February on record with a mean air temperature of 7.6°C). It was also a wet month: the 9th wettest February on record, though less wet than in 2001 and far less wet than 1941 when 152.5mm was recorded. However, at this time the 12-month rainfall total remained well below the long-term average, while 3-month and 6-month totals were close to average. Despite the rain, it was sunnier than usual and also a windy month with a gust of 54kt (100km/hr) on the 1st. Given the mild weather in January and February, the 2001-02 winter was, not surprisingly, one of the warmer ones on record, ranking 20th; a cool December brought down the average on what might otherwise have been a very warm winter indeed.
March was again a very mild month, 12th warmest on record since 1850. Even so, a March mean of 10.9°C has, remarkably, been exceeded five times since 1990, so by the standards of the last decade or so, it was not unusual. As expected, both mean maximum and mean minimum were well above average. There were, nevertheless, 14 ground frosts and 4 air frosts, suggesting cold, clear nights. This was borne out by sunshine hours being well above average, and rainfall somewhat below average. Even so, there were 17 “rain days” when more than 0.25mm rainfall was recorded. Generally, wind speeds were around normal for the time of year, but it was very breezy in the early part of the month with gusts of 51kt (95km/hr) on the 6th and 48 kt (89km/hr) on the 7th.
Mean air temperature in April was well above average – in fact, the warmest April in Durham since 1987 and the 8th warmest on record. Maximum temperatures in particular were well above average, minimum temperatures less so. It was a dry month, well below average: the driest April since 1997, and 17th driest since 1852. Overall, the 12-month total to April 2002 was well below the 12-month average, in stark contrast to conditions the previous year when the 12-month total to April 2001 was well above average. April was a sunny month, and for the first time since 1982, some sunshine was recorded every day.
May was another warm month, 16th warmest on record since 1850, although 0.3°C cooler than May 2001! There were few ground frosts and no air frosts. Rainfall was just a little above average and, given the large number of rain days, sunshine was a little below average. Not surprisingly, given that we had the 12th warmest March and the 8th warmest April, Spring 2002 turned out to be exceptionally warm (average 9.0°C), 2nd warmest on record, and only exceeded by 1945 (9.2°C). Rainfall in spring as a whole was a little below average, but not exceptionally so.
It did not feel like the 23rd warmest June on record! In fact, maximum temperatures were only about average, and it was warmer than usual nights that made the overall mean air temperature well above average, the warmest June since 1992. An absolute maximum of 21.3°C was, however, particularly disappointing, although one only has to go back to 1997 to find a lower figure. The amount of sunshine was also depressing, only 71% of the normal figure. Rainfall was, however, below average, with no rain recorded in the last 13 days. Wind speeds were above average. Altogether, it was a cloudy June with lower than normal daytime temperatures, making it feel like a poor start to the summer, even if mean temperatures were well above average and there was less rain than normal!
Given that the first six months of 2002 were all well above average temperature, it is of interest to see how the average temperature for the half-year compared to all other years at Durham since 1850. There were reports in the press stating that the first six months of 2002 had been the warmest on record in the northern hemisphere and this is true for Durham too. The average temperature of 8.57°C in 2002 exceeds that for 1990 by fully 0.04°C! The top ten values are as follows:
1999 – 8.05°C
1949 – 8.08°C
1868 – 8.10°C
1938 – 8.15°C
2000 – 8.17°C
1989 – 8.18°C
1992 – 8.30°C
1998 – 8.43°C
1990 – 8.53°C
2002 – 8.57°C
It is notable that most of these have occurred since 1989, and indeed only 2001 is absent from the last five years. The evidence of global warming is very clear in this regard. Of perhaps more interest is the fact that the 12-month average up to and including June 2002 is 10.02°C, the first time that a 12-month average has exceeded 10°C in the history of the Durham Observatory. (As it happens, the 12-month average to September 2002 was exactly the same.)
The mean air temperature was exactly equal to the long-term mean for July. Although this might again seem a disappointing result, it was only four years since we had had an even cooler July, but it was still below par compared to the year before. As in June, sunshine was well below average; unlike June however, rainfall was well above average. All together, July 2002 was therefore rather unsatisfactory: dull, wet and only modestly warm. A total of 30.6mm was recorded on the 31st; with another large fall only 3 days later, and then another 6 days after that, no wonder the early part of the summer holidays seemed so bad!
August was, like June and July, lacking in sunshine, and wetter and windier than usual. Despite this – and somewhat surprising, it was nevertheless the 6th warmest August on record, and the warmest since 1997. This shows that warm nights can make up for the lack of hot days in calculating the average. Even so, daily maximum temperatures were well above the long-term average and any perception of a ‘poor’ August was not borne out by the temperature results, only by the sunshine and rainfall data. There were notable falls of rain on the 2nd (32.2mm) and 8th (22.4mm); the former was the wettest August day in Durham since 4th August 1993 when 39.2 mm was recorded. Long-period rainfall totals remained above average as a result.
As already noted, the amount of bright sunshine was most disappointing, an hour and a half less each day than on average. There were five days without any sunshine at all, something not experienced in Durham in August since 1989.
September was another warm month, but although well above average, Septembers in 1998, 1999 and 2000 were all warmer. Overall, September 2002 was the 27th warmest on record since 1850. It was also a dry month, the 30th driest September on record, and but for 15mm on the 10th would have been very dry indeed. Even so, sunshine was below average and the total for the year so far is nearly 100 hours below the expected level. Wind speed was well down on average too.
October was a cool, wet month. All measures of temperature were below average, mean air temperature and mean maximum was the lowest since 1994, while mean minimum was the lowest since 1997. Although a wet month, it was only the wettest October since 1998. The number of days with no recorded sunshine was the largest since 1993. Given lower than normal temperatures, mean air temperature over the last twelve months fell slightly below the 10°C mark, but was still well above the long-term average. Long-term rainfall totals were, in contrast, now close to average.
November was a mild month, the 20th warmest on record since 1850. However, it was less warm than November 2001 (7.5°C), which was 10th warmest on record. Mean minima in particular were well above the long-term average and the highest since 1997. It was also a wet month, although not exceptionally so. All long-term measures of rainfall were now above average. As expected, it was a dull month, with hours of bright sunshine below average; there were 12 days with no sunshine recorded at all. Not surprisingly, there were very few ground frosts as a result, and only one air frost.
December was milder than normal because night-time temperatures were above average; daytime temperatures were exactly average for the month. The mean minimum was the highest since 1988. Mean air temperature ranked 123rd out of 154 and was the highest since 1994. It was a wet month, the wettest since 1990 and the 20th wettest December since 1852. Not surprisingly, there was very little bright sunshine, less than an hour per day. The total was the 2nd lowest on record (since 1950) and the lowest since 1978 when there was a meagre 9.7 hours for the whole month! As expected there were few air frosts and the number of ground frosts was equal lowest on record (with 1988) since 1961.
Overall, 2002 was a very warm year in Durham, the 2nd warmest on record (9.80°C) since 1850 and beaten only by 1949 (9.83°C). Only October fell below the long-term monthly mean. As noted above, in June and September, the 12-month running mean exceeded 10°C for the first time in Durham’s history. Of the 14 highest annual means, 8 have occurred since 1990. 2002 was also a wet year (734.2mm), well above the long-term mean (649mm). However, unlike temperature, the annual rainfall total was not record-breaking, ranking only 112nd highest in 151 years.
Professor Tim Burt
Department of Geography