The Weather at Durham in 2004

Despite two short spells of old-fashioned wintry weather, January was as a whole very mild, the 15th warmest on record. Both day – time and night – time temperatures were well above average. Rainfall was well above average too, by exactly one inch (25.4mm)! The three – and six – month totals were, as a result, close to average but the 12 – month total remained below average. Both sunshine and wind speed were a little below average.

There was some wintry weather in February too, but very warm days at the start of the month meant that it was, overall, a very warm month, the 9th equal warmest since 1850. The absolute maximum of 15.4°C was the 3rd highest since 1962. Rainfall in February was close to average. It was a sunnier month than normal, and a little windier than usual. For the winter as a whole, the mean air temperature was 5.1°C, the 6th equal warmest on record (with 1869 and 1990); in recent times, there have been warmer winters – 1989 (6.3°C) and 1998 (5.7°C), the other warmer winters being 1975, 1863 and 1935. The 12 – month running mean air temperature rose above 10°C for the 3rd time in Durham’s climatic history; most remarkably, the February value of 10.15°C was the highest on record – in other words, the 12 – month period up to and including February 2004 was at that point the warmest ‘year’ in Durham since records began – and indeed remains so. The 12 – month running mean remained above 10°C up to and including June, but the mean value of 10.15°C was not exceeded.

In March, yet again, temperatures were well above average. Mean air temperature was 19th highest since records began, although March was warmer in both 2002 and 2003. The 12 – month running mean stayed above 10°C for the second month running. It was a dry month, having only just over half the normal amount. Despite the lack of rain, sunshine was slightly below average. There was a gust of 111km/hr on the 19th.

April was another very warm month. Mean air temperature was the 2nd highest on record after 1949, and this contributed to the 2nd warmest start to a year after 1990. Mean daily minimum was the highest on record (Tabulated records are available only from 1950). There were very few ground frosts, only 3, the equal lowest April total since 1950 (with 1971 and 1987). As might be expected with such high night-time temperatures, it was a cloudy month. Sunshine was well below average, although only 4 days recorded no sunshine at all – the last 4 days of the month as it happened.

There were problems with the temperature recording equipment at the start of May and monthly values had to be estimated by comparison with nearby stations. On this basis, it seems clear that May was another warm month: mean maximum was the 9th equal highest for May since 1950 whilst mean air temperature was the 17th highest for May since 1850. It was a dry month, but not particularly sunny. It was the 3rd warmest spring on record, beaten only by 2003 and 1945.

June was a wet, dull month but, nevertheless, a warm one. The mean air temperature was the 10th equal warmest for June since 1850. Overall, it has been the warmest first half of a year on record. The top ten January – to – June averages are listed below and make interesting reading, the top eight all being since 1989.

1868 – 8.1
1938 – 8.2
2000 – 8.2
1989 – 8.2
1992 – 8.3
1998 – 8.4
2003 – 8.5
1990 – 8.5
2002 – 8.6
2004 – 8.8

Rainfall in June was above average. Sunshine levels were below average, and overall, the cumulative total was by then well down on average – and far behind 2003. June 2004 was windier than usual; this is somewhat unusual in that over recent years, mean wind speed has tended to be below average.

July was a dull, wet month of only average temperature, relatively disappointing in other words. Mean maximum temperatures were below average, the lowest since 2000 but, not surprisingly given the cloudy weather, mean minimum temperatures were somewhat above average. Overall, mean air temperature was just above average, but one only has to go back to 2002 to find an equally disappointing July – and July 2000 was a good deal cooler. July rainfall was a little above average; again, 2002 was wetter. Rain fell on 19 days, a relatively high total, and the largest number since 1998. It was a dull month too, with over an hour less sunshine per day on average than normal, though only the dullest since 2001. The sunniest day (26th) recorded only 10.2 hours. July was nevertheless a relatively calm month with wind speeds somewhat below average.

August was a warm but very wet month. Mean air temperature was 1.6°C above average, lower than last year, but still 11th highest since 1850. Mean minimum temperature was 2nd highest on record since 1950. The minimum on the night of the 8th / 9th was 16.8°C, a remarkably high value, and the next night was only marginally cooler. Most remarkable in August was the rainfall, more than twice the monthly average. The total of 156.8mm was the 6th highest for August since 1852, exceeded only in 1917, 1927, 1878, 1986 and 1956 (the August record with 175.7mm). The total of 52.2mm on the 9th was only the 14th daily total at Durham since 1881 of 50mm or over. 72.2mm fell on the 9th and 10th, associated with a decaying hurricane, and altogether 88.4mm fell in four days (9th – 12th). There was also a daily catch of 25mm on the 19th. Not surprisingly, long-term totals were now well above average, and the 12 – month running total was the highest since October 2001. Sunshine was again below average, another disappointing month. For the summer as a whole, an average temperature of 15.2°C placed 2004 as the 14th warmest on record since 1850, following 2003’s record breaker. It was the 11th wettest summer on record (289.6mm), the wettest since 1997. 1867 holds the summer rainfall record with 383.4mm; summers tended to be relatively wetter in the latter part of the 19th Century.

Unlike August, September was a dry month, with only a third of normal rainfall. Even so, there were 13 rain days. It was a mild month, with all three temperature measures one degree above average. Sunshine was a little above average too, only the second such month in a rather dull and disappointing year.

October was another very wet month, reversing the trend from September and sending long-term totals back well above average. It was the 18th wettest October since 1852 and the wettest since 2000, although the number of rain days was the same in both years. Remarkably, for the first and only time in 2004, monthly mean air temperature dipped below the long-term average, but only just (by less than 0.1°C)! Sunshine reverted to the usual pattern for 2004 and fell below average yet again.

November was another warm month, the 14th warmest November since 1850, although 2001 and 2003 were both warmer. Most remarkably, it was a very dry month, only 14.4mm, the second lowest November total on record since 1852. Nonetheless, there was a little less sunshine than normal, and the cumulative total for the year remained well below average. Overall, it was the 10th warmest autumn on record, but almost a degree cooler than the record – breaker in 2001.

December was another warm month, not quite as far above average as November but still ranking 124th highest in a series of 155. Daily maxima were in particular well above average. This was reflected in a sunny month, a good deal sunnier than November in fact. It was also a very dry month: whilst there must be some doubt about a figure as low as 8.2mm, only 17mm was recorded at Ferryhill, so hopefully the total is reliable. That being the case, it was the 3rd driest December since 1852, only 1871 and 1852 being drier. There was a gust of 102km/hr on the 23rd.

2004 was another remarkably warm year, the warmest on record at Durham since records began in 1850, the mean of 9.95°C beating the previous highest (2003) by 0.05°C. It was quite a wet year too, the total of 726mm ranking 110th in a series of 153. There were far fewer hours of bright sunshine than normal, however; the total was the 16th lowest since 1881, making 2004 a dull and disappointing year in that respect. It only goes to show that global warming does not necessarily mean unbroken sunshine!

Addendum

Adjustments to the rainfall record

Regular readers will have noticed my concern about some of the recorded rainfall totals over recent time, since indeed we moved to an automatic weather station in 1999. It has become apparent that, unless the automatic rain gauge is checked very regularly, it can easily become blocked and fails to record any rain (which presumably just sits in the funnel and gradually evaporates). I hope that a regular maintenance programme is now in place but it does mean that I have had to adjust the long-term record. This has been done using the nearby Barkers Hough gauge (data kindly supplied by Rachel Merrix at the Environment Agency); the two gauges have a very high correlation so any deviation is immediately obvious.

I give below my best estimate of the ‘correct’ Durham rainfall record since 1999. Any month that has been adjusted is in red; italics indicate that little or no rain was recorded at the Observatory; a bold figure shows that some rain was recorded at the Observatory but the record for the entire month was in doubt. In both cases the Barkers Hough gauge has been used to calculate a monthly total for the Observatory.

One consequence of the recalculation is that the very low total for 2003 reported last year has been adjusted upwards so that, although it remains a low amount, it was by no means as extreme as previously indicated.

Year	1999	2000	2001	2002	2003	2004
January	57.5	34.3	50.2	34.4	63.0	84.4
February	15.6	28.7	100.7	87.6	6.6	73.7
March	92.7	20.8	56.4	39.4	14.4	28.3
April	45.2	150.0	59.0	14.8	14.8	67.6
May	50.2	44.4	7.8	57.6	57.7	19.8
June	67.2	90.2	64.1	42.0	102.1	68.6
July	12.1	43.0	42.4	84.0	56.8	64.2
August	81.3	44.0	74.2	91.8	28.6	156.8
September	52.7	88.0	66.9	25.2	94.2	19.6
October	39.0	111.0	71.7	86.0	37.8	120.4
November	26.8	150.8	35.8	80.4	44.1	14.4
December	63.7	68.0	35.0	91.0	67.2	8.2
Total	604	873.2	664.2	734.2	587.3	726.0

Professor Tim Burt
Department of Geography
Durham University