June got the Summer off to a good start with a warm, dry and sunny month.

Although the last 10 days of the month were very warm and the mean temperature in June was 1.2°C above average, a few cool days also occurred, mainly around mid-month. For instance, the maximum temperature on 1^st was only 14.1°C (the lowest day maximum of the month) whilst on 19^th the temperature peaked at no higher than 14.5°C. The highest temperature recorded in June was 29.5°C on 27^th. This temperature has been exceeded in June in only 7 years since 1972.

The lowest night minimum temperature in the month of 4.6°C and lowest grass minimum temperature of 1.6°C both occurred on 17^th. These temperatures did not herald a cool day to follow, however, as the temperature soared to a maximum of 22.7°C on 17^th. On 29^th the highest night minimum temperature (16.3°C) in June occurred.

The mean daily maximum temperature in June was 22.1°C, which is 2.2°C above average. The mean night minimum temperature in the month was 0.2°C above average at 10.8°C. It was the warmest June since 2006. An interesting feature of the month was that the temperature means and extremes were all very similar to June last year.

The mean earth temperature at 30 cms depth as observed at 0900 GMT daily was 17.2°C, peaking at 20.4°C on 29^th and 30^th, and falling to a minimum of 14.7°C on 2^nd.

June was a dry month, particularly the second half, and would have been a very dry month but for a heavy burst of rainfall in the afternoon of 6^th as a band of heavy showers tracked eastwards across the region. Rainfall on 6^th totalled 22.3 millimetres and this followed the trend over the last 30 years for the 6^th to be wetter than any other day in June. The mean daily rainfall on 6^th in the period 1981/2010 is 5.3 millimetres, compared with the next wettest day (1^st) with a much lower daily mean of 2.7 millimetres.

Total rainfall in June was 42.3 millimetres, which is 84% of the 1971/2000 average. The number of "rain days" (0.2 millimetres or more) in June was 10, with rainfall exceeding 1.0 millimetre on 6 of these days. Thunder was heard on just 1 day (6^th) in the month.

It has been reported that it has been the driest first half of the year in some parts of the country since 1929, but Royston has fared better than this since rainfall here for the first 6 months of 2010 was 228.1 millimetres (84% of normal), making it the driest first half of the year since 2006 only.

The first half of June was rather dull and sunshine struggled to keep up to the average for this period but a much sunnier second half of June brought sunshine to 20% above the 1971/2000 average at 216.8 hours. To illustrate this point daily mean sunshine for 1^st/15^th was 5.3 hours, increasing to a daily mean of 9.3 hours for 16^th/31^st.

The sunniest day in June was 3^rd with 16.0 hours sunshine whilst 4^th and 23^rd both accumulated 15.3 hours sunshine. Only 1 day in June (1^st) was completely sunless, although 10^th and 18^th could only manage 1 minute and 2 minutes sunshine respectively.

June was a relatively calm month and the highest wind gust speed recorded was 25 mph on 10^th. This is the lowest maximum wind gust speed in any month since at least 1997. The mean wind speed over the whole month was 4.2 mph. The highest daily (00/00 GMT) mean wind speed was 7.0 mph on 10^th, whilst the lowest daily mean wind speed was 1.9 mph on 3^rd.

The analysis of wind directions as observed daily at 0900 GMT reveals that these were fairly evenly spread over the month, as follows: NORTH 4 days, NE 5, E 2, SE 3, S 3, SW 2, W 5, NW 6 and CALM 0.

The mean MSL air pressure in June was 1017.0 mB, which is equal to the 30 Year (1976/2005) average. The highest and lowest air pressure values in June were 1028.9 mB on 15^th and 16^th, and 999.6 on 8^th, respectively.

The mean relative humidity in the month was 70.8%. The highest daily (00/00 GMT) mean relative humidity was 89.1% on 10^th whilst the lowest daily mean relative humidity was 52.2% on 28^th. The absolute lowest relative humidity reading in June was 29% at 1350 GMT on 28^th.

No fog (visibility < 1000 metres @ 0900 GMT) was observed in June.

Met. Observer, Royston (Iceni) Weather Station

6^th July 2010