March was an exceptionally dry month in Royston, whilst sunshine and temperatures were both above average, although the latter by only a narrow margin.

The drier than average conditions in February intensified in March and close to the end of the month it looked likely that it would be the driest March in the Royston rainfall record going back to 1853. However, a light fall of rain of 2.8 millimetres on 30^th March was enough to head off this potential record and in the event it was the driest March since 1961 only.

This made 30^th the wettest day of the month despite the relatively low rainfall total that day. The number of "rain days" (0.2 millimetres or more) in the month was 5 with rainfall exceeding 1.0 millimetre on 1 day only.

Total rainfall in March was 4.4 millimetres, which is only 11% of the 30 Year (1981/2010) average. The rainfall total for the first 3 months of the year was 109.4 millimetres, which is 85% of average.

March commenced on a rather cold note and temperatures remained below average for much of the first 3 weeks of the month, but significantly milder conditions thereafter raised the mean temperature by the end of the month to just above average. It was the mildest March since 2009 only, however.

The mean daily maximum temperature in March was 11.6°C, which is 0.9°C above the 30 Year (1981/2010) average. The mean night minimum temperature was 0.1°C below average at 3.5°C.

The highest daily maximum temperature recorded in the month was 17.8°C on 23^rd. This value is by no means exceptional, having been exceeded in March in 9 of the last 40 years. In contrast the lowest daily maximum temperature was 3.5°C on 1^st.

At the other end of the scale the lowest night minimum temperature in March was –2.5°C on 8^th, the highest night minimum temperature being 9.4°C on 22^nd. The lowest grass minimum temperature in the month was –7.5°C, also on 8^th. Totals of 5 air frosts and 11 ground frosts were recorded in March. Air frost duration in the month was 21.8 hours.

The mean earth temperature at 30 cms depth as measured at 0900 GMT daily was 7.1°C. The earth temperature varied during the month from a high of 9.2°C on 26^th to a low of 5.1°C on 8^th.

March commenced on a rather dull note with 2 of the first 3 days being completely sunless. Two further sunless days occurred on 15^th and 16^th but otherwise fairly sunny conditions predominated and by the month end the cumulative sunshine total of 134.4 hours reached 126% of the 30 Year (1971/2000) average. The sunniest day of the month was 24^th with 11.4 hours sunshine and 5 other days (7^th, 8^th, 14^th, 19^th and 25^th) exceeded 10 hours sunshine.

March can often be a windy month but only a small number of days would fit into that category this year. The highest wind gust speed recorded this March was 44mph on 31^st, the next highest daily maximum wind gust speed being 37 mph on 10^th.

The highest daily (00/00 GMT) mean wind speed was 14.1 mph on 31^st whilst the lowest daily mean wind speed was 1.8 mph on 7^th.

Wind directions as noted at 0900 GMT daily were fairly evenly spread through the month as the following analysis shows.: NORTH 3 days, NE 6, E 4, SE 1, S 5, SW 7, W 2, NW 3 and CALM 0.

The mean MSL air pressure in March was 1021.7 mB, which is almost 7 mB above the 30 Year (1981/2010) average. The highest and lowest air pressure values recorded in the month were 1041.2 mB on 23^rd and 995.7 mB on 13^th respectively.

The mean relative humidity in March was 80.9%. The highest daily (00/00 GMT) mean relative humidity was 95.5% on 16^th; the lowest daily mean relative humidity was 67.1% on 19^th.

The absolute lowest relative humidity reading in March was 39% at 1415 GMT on 19^th.

Fog (visibility < 100 metres at 0900 GMT) was observed on only 1 day (16^th) in March. On this day the fog was thick and visibility fell below the 200 metres threshold.

Met. Observer, Royston (Iceni) Weather Station

5^th April 2011