August 2023
SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY
August 2023
Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)
Mean daily maximum: 19.6 Difference from average: -0.2
Mean daily minimum: 11.7 Difference from average: +0.4
Mean air temperature: 15.7 Difference from average: +0.1
Absolute maximum: 25.6 (10th)
Absolute minimum: 6.7 (7th, 31st)
Mean grass minimum: 10.1 Difference from average: +0.9
Absolute grass minimum: 4.6 (7th, 31st)
Mean concrete minimum: 12.0
Absolute concrete minimum: 6.9 (7th)
Number of ground frosts: 0 Difference from average: 0
Number of air frosts: 0 Difference from average: 0
Mean soil temperature at 300 mm depth: 17.3
Mean soil temperature at 1000 mm depth: 14.9
Rainfall (all totals in millimetres; all averages 1991-2020)
Total for the month: 82.6 Difference from average: +16.4
Percentage of the average: 125%
Wettest day: 33.4 (14th)
Number of rain days (>0.1 mm): 15 Difference from average: -1
Number of wet days (=>1.0 mm): 12
3-month total rainfall to 31st August 2023: 246.6 Difference from average: +57.2
6-month total rainfall to 31st August 2023: 377.2 Difference from average: +50.8
12-month total rainfall to 31st August 2023: 786.2 Difference from average: +105.2
Sunshine (all totals in hours; all averages 1991-2020)
Total for the month: 158.6 Difference from average: -8.0
Percentage of the average: 95%
Mean daily sunshine: 5.4 Difference from average: -0.1
Sunniest day: 8.8 (11th)
Number of days with no recorded sunshine: 4
Note that the monthly sunshine total is now calculated from the UKMO E&NE regional total. Daily sunshine totals quoted here and in the data summary are uncorrected.
Wind (kph; all data from the West Building roof, Lower Mountjoy campus)
Average wind speed: 5.0
Maximum gust: 51.5 (2nd, 19:45, NNE)
Comments on August 2023
Like July, August was a disappointing month for temperatures. There was just one day with a maximum above 25 °C compared to an average of 2; in August 2022 we had 6 days above 25 °C! The mean air temperature was just above the 1991-2020 average, and it was the equal 33rd warmest August since 1844, so not too bad looking at the long record, but 11 Augusts have been warmer since 2000. There was one rain day fewer than normal, but even so it was a wet month, with 125% of average, the 39th wettest August since 1868. Although disappointingly wet, it was nowhere near the wettest August on record at Durham: 175.7 mm in 1956, but still in marked contrast to just 13 mm last year! The fall of 33.4 mm on the 14th is the 21st wettest August day since 1850 (n = 5394). The sunshine total was just below average and there were 4 days with no recorded sunshine. Again, the contrast with August 2022 is notable: a total of 221.6 hours of bright sunshine.
It was the 12th warmest summer on record (15.62 °C; average 15.0 °C), thanks in large part to the very warm June. The warmest day of the summer was nevertheless in July (27.8 °C, 8th July). July was marginally the warmest month, but all three months had very similar mean air temperatures (15.51 °C, 15.74 °C July, 15.68 °C August). Only 7 days exceeded 25 °C, 4 of them in June, rather disappointing compared to 14 last year but still 2 better than average. Despite a dry June, it was a wet summer (246.6 mm, 130% of average, 21st wettest since 1868). July especially and August were duller than average, but a very sunny June meant that overall, the total amount of summer sunshine was just a little above average (107%).
Emeritus Professor Tim Burt
Department of Geography
Durham University