June 2004

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

Mean daily maximum: 18.7
Difference from average: +1.2

Mean daily minimum: 10.1
Difference from average: +1.5

Mean air temperature: 14.4
Difference from average: +1.4

Absolute maximum: 24 (14th)

Absolute minimum: 3.3 (21st)

Mean grass minimum: 9.9

Absolute grass minimum: 5 (22nd)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 16.1

Mean soil temperature at 100cm depth: 14.3

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

Total for the month: 68.6
Difference from average: +16.8

Percentage of the average: 132%

Wettest day: 17.8 (18th)

Number of rain days (>0.25mm): 14

Number of wet days (=> 1mm): 12

3-month total rainfall to 30th June: 153.8
Difference from average: +2.0

6-month rainfall total to 30th June: 307.6
Difference from average: +4.1

12-month rainfall total to 30th June: 576.1
Difference from average: -62.9

Humidity
(Averages for 09:00 hours GMT)

Relative Humidity: 71.1%

Sunshine
(all averages 1961 – 1990)

Total for the month: 143.5 hours
Difference from average: -20.2

Percentage of the average: 87.7%

Mean daily sunshine: 4.8 hours
Difference from average: -0.7

Sunniest day: 12.1 hours (14th)

Number of days with no recorded sunshine: 1

Cumulative total sunshine since 1st January: 618.3 hours
Difference from average: -71.8

Wind

The mean wind speed: 12.8km/h [6.9kt]
Difference from average: +1.3km/hr

The highest gust: 59.2km/h [32kt] from 290° at 23.15 GMT on 23rd

ISSN1350-483

Comments on June 2004
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 was above average, and 3- and 6- month totals have now returned to average; the 12-month total remains well below average, however.

Sunshine levels were below average, and overall, the cumulative total is 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.

Professor Tim Burt
Department of Geography
Durham University