August 2003

Temperatures
(all temperatures in degrees Celsius; all averages 1961 – 1990)

Mean daily maximum: 21.1
Difference from average: +1.1

Mean daily minimum: 12.2
Difference from average: +1.8

Mean air temperature: 17.0
Difference from average: +2.3

Absolute maximum: 28.6 (10th)

Absolute minimum: 6.7 (15th)

Mean grass minimum: 9.8

Absolute grass minimum: 3.7 (15th)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 17.9

Mean soil temperature at 100cm depth: 16.9

Rainfall
(all totals in millimetres; all averages 1961 – 1990)

Total for the month: 9.6
Difference from average: -57.5

Percentage of the average: 14%

Wettest day: 6.2 (11th)

Number of rain days (>0.25mm): 4

Number of wet days (=> 1mm): 2

3-month total rainfall to 31st August 2003: 100.8
Difference from average: -70

6-month rainfall total to 31st August 2003: 169.6
Difference from average: -152.4

12-month rainfall total to 31st August 2003: 521.8
Difference from average: -127.2

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 73.9%

Sunshine
(all averages 1961 – 1990)

Total for the month: 152.2 hours
Difference from average: -3.3

Percentage of the average: 98%

Mean daily sunshine: 4.9 hours
Difference from average: -0.1

Sunniest day: 10.6 hours (4th)

Number of days with no recorded sunshine: 3

Cumulative total sunshine since 1st January: 1121.7 hours
Difference from average: +120.6

Wind

The mean wind speed: 9.3km/h [5.0kt]
Difference from average: -2.4km/hr

The highest gust: 61km/h [33kt] from 221° at 13:43 GMT on 21st.

ISSN1350-483

Comments on August 2003
August was a warm, dry month, but with only average sunshine. Although at times it felt exceptionally warm, in fact the mean daily maximum temperature was only the 9th highest on record since 1950, whilst the mean daily minimum temperature was the 4th highest on record since 1950. Together, these provided a mean air temperature of 17°C, 5th warmest on record since 1850 (behind 1947, 1995, 1997 and the record holder 1975, 17.6°C). The absolute maximum of 28.6°C on the 10th was the 6th highest since 1962 but well below the record holder 1990, 32.5°C.

It was a dry month with only 9.6 mm rainfall recorded. Not surprisingly the highest daily rainfall, only 6.2mm, was the lowest such total since 1972. Not surprisingly, again all the longer-period totals remain well below average. Despite this dryness, there was only an average amount of bright sunshine.

Looking at the summer as a whole, it turns out to be the warmest summer on record in Durham since records began in 1852, 16.3°C beating the previous record from 1933 (16.1°C). It was also the driest summer since 1995. Using the Davis Index of summer, which weights average temperature, rainfall and sunshine values for the months of June, July and August, 2003 ranks the 14th best summer since 1886; 1976 tops the rankings. On this basis, we can expect as good a summer as this around once a decade on average.

Professor Tim Burt
Department of Geography
Durham University