June 2015

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

Mean daily maximum: 17.0
Difference from average: -0.5

Mean daily minimum: 7.8
Difference from average: -0.8

Mean air temperature: 12.4
Difference from average: -0.6

Absolute maximum: 26.4 (30th)

Absolute minimum: 1.5 (15th)

Mean grass minimum: 5.6

Absolute grass minimum: -0.5 (15th)

Number of ground frosts: 1

Number of air frosts: 0

Mean soil temperature at 30cm depth: 13.9

Mean soil temperature at 100cm depth: 12.3

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

Total for the month: 34.8
Difference from average: -17.1

Percentage of the average: 67%

Wettest day: 6.8 (8th)

Number of rain days (>0.25mm): 8

Number of wet days (=> 1mm): 6

3-month total rainfall to 30th June: 129.4
Difference from average: -42.6

6-month rainfall total to 30th June: 239.2
Difference from average: -107.0

12-month rainfall total to 30th June: 520.6
Difference from average: -128.4

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 74%

Sunshine
(all averages 1961 – 1990)

Total for the month: 138.7 hours
Difference from average: -25

Percentage of the average: 84%

Mean daily sunshine: 4.6 hours
Difference from average: -0.9

Sunniest day: 11.2 hours (11th)

Number of days with no recorded sunshine: 1

Cumulative total sunshine since 1st January: 733.2 hours
Difference from average: 83.1

ISSN1350-483

Comments on June 2015
June was the first month with below-average temperature since last August, equal 43rd lowest on record since 1850, but only the lowest since 2012. The mean maximum was equal 37th lowest since 1900 while the mean minimum was equal 30th lowest (rather different to the 5th highest last year). The warmest day of the month was the last, the best June day since 2011. We eagerly await the value for 1st July!

It was a dry month, the 56th driest June since 1850. Several days received a total of at least six millimetres but none received seven! All long-period rainfall totals are now well below average.

There was a disappointing amount of bright sunshine, less than in both April and May, but still almost twice the total in 2012, and an hour a day more than last year.

Professor Tim Burt
Department of Geography
Durham University