After the drier and warmer than average months of June and July much cooler and wetter conditions set in during August which turned out to be a cool, very wet and very dull month.

August was most notable for the amount of rainfall which occurred at frequent intervals throughout the month, considerably interfering with the local grain harvest. It was the wettest August since 1912, second wettest August since 1853 when rainfall records for Royston are first available, and the wettest month of any since June 1958.

The high rainfall total was mostly achieved without any thundery outbreaks, the only thunder heard in the month being a few claps at 0345 GMT on 22^nd.

August failed to produce the warmth of the previous two months of Summer and the absolute maximum temperature recorded in the month (25.0°C on 9^th) was the 3^rd equal lowest in August since the commencement of records at this station in 1972 (after 24.9°C in 1980, 23.8°C in 1986 and 25.0°C in 2008).

The lowest night minimum temperature in August was 7.2°C on 31^st. The month’s lowest grass minimum temperature of 3.9°C also occurred on this date. In contrast, the highest night minimum temperature of the month was 18.5°C on 21^st. On 4^th the maximum temperature only managed to reach 17.1°C, the lowest such value of the month. It was the coolest August in Royston since 1993.

The mean daily maximum temperature in August was 20.8°C, which is 1.6°C below the 30 Year (1976/2005) average. The mean night minimum temperature in August of 12.3°C was similarly below average but by only 0.4°C.

The mean earth temperature at 30 cms depth as recorded at 0900 GMT daily was 17.7°C. The highest and lowest earth temperature values in the month were 19.1°C on 10^th and 15.8°C on 31^st  respectively.

In the light of the aforementioned cool and wet conditions in August it is not surprising that it was a very dull month, the dullest August since at least 1997, in fact. Total sunshine in the month was 120.6 hours, which is only 65% of the 1971/2000 average.

The sunniest day in August was 31^st with 11.8 hours sunshine. No other day exceeded 10 hours sunshine but on a slightly more positive note only 1 day (26^th) in the month was completely sunless (although 1^st produced only half a minute of sunshine!).

August was a rather breezy month for the Summer season and the mean wind speed throughout the whole month was 6.1 mph. The highest wind gust recorded was 38 mph at 1405 GMT on 29^th. The highest daily (00/00 GMT) mean wind speed in the month was 11.3 mph on 24^th, whilst the lowest daily mean wind speed was 1.8 mph on 31^st.

The analysis of daily wind directions as observed at 0900 GMT shows a strong bias towards SW and W winds, as follows: NORTH 3 days, NE 1, E 1, SE 0, S 2, SW 9, W 10, NW 5 and CALM 0.

The mean MSL air pressure was 1013.1 mB, which is 4 mB below the 30 Year (1976/2005) average. The highest and lowest air pressure values in August were 1026.9 mB on 31^st and 992.9 mB on 23^rd respectively.

The mean relative humidity in August was 78.0%. The highest daily (00/00 GMT) mean relative humidity was 92.6% on 26^th, whilst the lowest daily mean relative humidity value was 65.1% on 9^th. The absolute lowest relative humidity reading in August was 35% at 1350 GMT on 9^th.

Fog (visibility < 1000 metres at the 0900 GMT observation hour) was not observed on any day in August.

SUMMER (June/ August) 2010: The mean daily maximum temperature in Summer was 22.4°C, which is 0.9°C above the 30 Year (1976/2005) average. The mean night minimum temperature in Summer was 0.5°C above average at 12.5°C. It was the warmest Summer in Royston since 2006.

Total rainfall in Summer was 212.0 millimetres, which is 148% of the 1971/2000 average. This was the highest Summer rainfall total since 1997. Summer sunshine was 91% of the 1971/2000 average at 505.6 hours.

Met. Observer, Royston (Iceni) Weather Station

8^th September 2010

Return to  Daily Weather Observations - August 2010   header page