It was a very warm and dry July in Royston, but rather dull.

Although it was the warmest July since 2006 only, perhaps more significantly it was the 5^th warmest July since 1972 (when records began), after July 2006, 1995, 1994, and 1983. Also, the temperature exceeded 30°C for the first time (in any month) since 26^th July 2006, and failed to reach 20°C on only 1 day (13^th) in the month.

The highest daily maximum temperature recorded in July was 31.3°C on 9^th. The equivalent value just 4 days later on 13^th was 19.5°C, the lowest daily maximum temperature of the month. The lowest night minimum temperature in July was 10.0°C on 6^th, and on this date the grass minimum temperature also fell to its lowest value (6.6°C) of the month. The highest night minimum temperature of the month was 18.0°C on 2^nd.

The mean earth temperature at 30 cms depth as observed at 0900 GMT daily was 19.7°C. The highest and lowest earth temperatures recorded in the month were 21.2°C on 12^th and 18.5°C on 30th respectively.

The drought like conditions experienced in the latter half of June continued for most of July. For example the rainfall in the 31 days from 11^th June was only 2.9 millimetres, and from 11^th June to 26^th July inclusive (46 days) was only 11.1 millimetres. Total rainfall in July was 20.4 millimetres, which is 47% of the 30 Year (1971/2000) average. It was the driest July since 1994.

The number of "rain days" (0.2 millimetres or more) in July was 11, whilst rainfall exceeded 1.0 millimetre on 6 of these days. The wettest day of the month was 27^th with 6.8 millimetres rainfall. Thunder was heard on just 1 day (22^nd) in July.

The cumulative total of rainfall for 2010 to the end of July stands at 248.5 millimetres, which is 79% of normal.

Although in the first half of July sunshine exceeded 10 hours on 4 separate days, the month ultimately turned out to be a rather dull month with total sunshine of 168.2 hours being only 88% of the 1971/2000 average. It was the dullest July in Royston since 2000.

The sunniest day in July was 10^th with 14.1 hours sunshine. Only 1 day (13^th) in the month was completely sunless.

July was a rather breezy month at times and the mean wind speed over the whole month was 6.3 mph. The maximum wind gust speed recorded in the month was 37 mph, which occurred on both 15^th and 16^th. The highest daily (00/00 GMT) mean wind speed was 12.9 mph on 15^th whilst the lowest daily mean wind speed was 2.5 mph on 13^th.

South westerly winds were in the ascendancy in July as indicated by the following analysis of wind directions as observed at 0900 GMT daily: NORTH 1 day, NE 2, E 0, SE 1, S 4, SW 13, W 6, NW 4, and CALM 0.

The mean MSL air pressure in July was 1014.3 mB, which is 3 mB below the 30 Year (1976/2005) average. The highest and lowest air pressure values recorded in the month were 1026.0 mB on 6^th and 998.3 mB on 15^th respectively.

The mean relative humidity in July was 66.5%. The highest daily (00/00 GMT) mean relative humidity was 84.1% on 13^th. At the other end of the scale the lowest daily mean relative humidity was 48.2% on 20^th. The absolute lowest relative humidity reading in the month was 27% at 1020 GMT on 19^th. The timing of this minimum humidity value is somewhat unusual in that the lowest monthly value does not normally occur this early in the day.

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

Met. Observer, Royston (Iceni) Weather Station

6^th August 2010