Temperatures, rainfall and sunshine were all below average in July!

Although July commenced with a fairly warm first week, temperatures were thereafter unexceptional culminating with an unremarkable highest temperature (25.8°C) of the month on 31^st. The absolute maximum temperature in July has been lower than this in only 5 years since 1972.

The mean daily maximum temperature in July was 21.4°C, which is 1.3°C below the 30 Year (1981/2010) average. The mean night minimum temperature in the month was 11.5°C, which is 1.4°C below average. On these figures it was the coolest July in Royston since 2000.

The lowest night minimum temperature recorded in July was 7.7°C on 22^nd whilst the lowest grass minimum temperature of the month was 4.6°C on 30^th.

In contrast, the highest night minimum temperature in July was 14.4°C on 16^th. On 13^th the highest temperature reached during the day was only 17.0°C, making this the coolest day of the month.

The mean earth temperature at 30 cms depth as recorded at 0900 GMT daily was 17.8°C. The highest and lowest earth temperature values were 19.0°C and 16.7°C on 12^th and 24^th respectively.

The July rainfall failed to make up for any of the deficit accumulated during the very dry Spring, the month’s rainfall of 36.2 millimetres being only 70% of the 30 Year (1981/2010) average. It was not as dry as July last year, but prior to 2010 it as the driest July since 2005.

The number of "rain days" (0.2 millimetres or more) in July was 12, with rainfall exceeding 1.0 millimetre on 6 of these days. The wettest day of the month was 16^th with 11.9 millimetres rainfall. July ended on a dry note, no measurable rainfall being recorded from 23^rd to 31^st inclusive

Rainfall in 2011 to the end of July amounted to 230.9 millimetres, which is 71% of average. This represents a deficit of 92.2 millimetres rainfall so far this year.

Thunder was heard on just 1 day (17^th) in July.

Some sunshine at least was recorded on every day in July but this did not prevent the month’s total from falling 9% short of the 30 Year (1971/2000) average. Total sunshine in July was 173.6 hours, which came as a disappointment after the 3 months April, May and June each registered over 200 hours sunshine.

The sunniest day in June was 24^th with 12.0 hours sunshine. It was not as dull as in July last year, but prior to 2010 it was the dullest July since 2000.

The mean wind speed in July was 5.2 mph, whilst the maximum wind gust speed recorded in the month was 34 mph on 8^th. The highest daily (00/00 GMT) mean wind speed was 10.8 mph on 18^th and the lowest daily mean wind speed was 2.4 mph on 11^th.

In the analysis of wind directions as observed at 0900 GMT daily, winds from the N and NW accounted for half of the days in the month. The full analysis is NORTH 8 days, NE 1, E 1, SE 1, S 4, SW 5, W 3, NW 8 and CALM 0.

The mean MSL air pressure in the month was 1012.7 mB, which is 3.5 mB below the 30 Year (1981/2010) average. The highest air pressure value recorded in July was 1026.5 mB on 1^st, whilst the lowest such value recorded in the month was 990.0 mB on 17^th.

The mean relative humidity in July was 74.7%. The highest daily (00/00 GMT) mean relative humidity value was 87.6% on 19^th. The lowest daily mean relative humidity value in the month was 57.4% on 15^th.

The absolute lowest relative humidity reading in July was 34% at 1535 GMT on 14^th and at 1210 GMT on 15^th.

Fog (visibility < 1000 metres @ 0900 GMT) was not observed on any day in July.

Met. Observer, Royston (Iceni) Weather Station

5^th August 2011