June 2017

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

Mean daily maximum: 18.4
Difference from average: +0.7

Mean daily minimum: 11.2
Difference from average: +2.6

Mean air temperature: 14.8
Difference from average: +1.6

Absolute maximum: 27.3 (18th)

Absolute minimum: 7.8 (26th)

Mean grass minimum: 9.8

Absolute grass minimum: 5.1 (26th)

Mean concrete minimum: 11.2

Absolute concrete minimum: 7.4 (26th)

Number of ground frosts: 0

Number of air frosts: 0

Mean soil temperature at 30cm depth: 15.9

Mean soil temperature at 100cm depth: 14.0

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

Total for the month: 103.4
Difference from average: +51.6

Percentage of the average: 199%

Wettest day: 25.8 (6th)

Number of rain days (>0.25mm): 12

Number of wet days (=> 1mm): 11

3-month total rainfall to 30th June: 152.2
Difference from average: -19.8

6-month rainfall total to 30th June: 318.3
Difference from average: -27.9

12-month rainfall total to 30th June: 642.3
Difference from average: -6.7

Humidity
(averages for 09:00 hours GMT)

Relative Humidity: 78%

Sunshine
(all averages 1961 – 1990)

Total for the month: 118.3 hours
Difference from average: -45.4

Percentage of the average: 72%

Mean daily sunshine: 3.9 hours
Difference from average: -1.6

Sunniest day: 14.3 hours (1st)

Number of days with no recorded sunshine: 6

Cumulative total sunshine since 1st January: 694.5 hours
Difference from average: +4.4

ISSN1350-483

Comments on June 2017
This was the 7th equal warmest June at Durham since 1850. Whilst the mean maximum temperature was only modestly above average (but still the 40th highest since 1900), the mean minimum air temperature was the highest on record for June. The absolute minimum on the night of 17th was the highest June minimum since 1997 (equalled in 2006). There were three very warm June days in the middle of the month with 27.3°C on 18th being the 36th hottest June day since 1850 (n=5040).

There was almost double the average rainfall for June, the wettest June since 2012 and overall the 9th wettest June since 1850. Sunshine was well below average, not quite as bad as last year, but still the 15th equal lowest total for June since 1882. No doubt the amount of cloud cover influenced the high night-time temperatures noted above.

Professor Tim Burt
Department of Geography
Durham University