Royston (Iceni) Weather Station

Daily Weather Observations - November 2008

Temperatures and sunshine were near average in November in Royston, but it was a rather wet month.

The absolute maximum temperature in November of 14.4°C on 14^th was unexceptional and was, in fact, the 6^th lowest in November since 1972. However, the mean daily maximum temperature was precisely equal to the 30 Year (1976/2005) average at 9.7°C.

The mean night minimum temperature was 5.3°C, which is 0.4°C above the 30 Year average. The lowest temperature recorded in the month was –2.2°C on 23^rd. The lowest grass minimum temperature in the month of –6.0°C was also recorded on this date. Totals of 3 air frosts and 7 ground frosts were recorded in November. Air frost duration in November was 23.4 hours. It was the coldest November in Royston since 2005 only.

The mean earth (30 cms depth) temperature as read at 0900 GMT daily in November was 8.2°C. The highest and lowest earth temperature values in November were 10.0°C and 6.0°C on 7^th and 26^th respectively.

November commenced on a wet note with 20.3 millimetres rainfall on 1st, making this not only the wettest day of the month, but also the wettest 1^st November since at least 1972. (The mean rainfall for 1^st November over the 30 Year period 1976/2005 is 1.1 millimetre).

Apart from 10^th (10.9 millimetres rainfall) daily amounts of rainfall for the rest of the month were fairly modest, but the rainfall total for the month of 77.4 millimetres nonetheless exceeded the 30 Year (1971/2000) average by 48%. The number of "rain days" (0.2 millimetres or more) in the month was 20 with rainfall exceeding 1.0 millimetre on 13 of these days.

After the surprise October snowfall all November could manage was a light covering of snow grains on the morning of 23^rd. Rainfall duration in November was 84.3 hours. It was the wettest November since 2005.

The year 2008 is set to be a wetter than average year as rainfall for the first 11 months has already exceeded the 1971/2000 annual average by 43.7 millimetres.

Although sunshine was not far from the 30 Year (1971/2000) average it could not match the average of the last 10 years, which period has seen a much sunnier regime in November. Total sunshine in November was 65.9 hours, which is 97% of the 1971/2000 average, but this drops to 75% of the shorter non-standard 1998/2007 sunshine average. Needless to say it was the dullest November since at least 1997.

The sunniest day in November was 11^th with 7.1 hours sunshine closely followed by 22^nd with 6.9 hours sunshine. The number of days in the month with no sunshine at all was 11, and this was the highest such figure in any month since the 12 days in December 2006.

The mean wind speed in November was 5.6 mph. The maximum wind gust recorded in the month was 46 mph on both 9^th and 10^th.

The highest daily (00/00 GMT) mean wind speed in November was 12.1 mph on 9^th, whilst the lowest daily mean wind speed was 0.5 mph on 2^nd.

The analysis of wind directions as observed at 0900 GMT daily shows a fairly even distribution as follows: NORTH 5 days, NE 3, E 1, SE 1, S 4, SW 4, W 7, NW 3 and CALM 2.

The mean MSL air pressure in the month was 1010.1 mB, which is almost 5 mB below the 30 Year (1976/2005) average. The highest and lowest air pressure values in November were 1034 mB and 983 mB on 17^th and 23^rd respectively.

The mean relative humidity in November was 93.4%. The highest daily (00/00 GMT) mean relative humidity was 100.0% on 30^th, an unusual day of saturated air for the whole 24 hours. The lowest daily mean relative humidity was 73.6% on 22^nd. The absolute lowest relative humidity reading in November was 39% at 1405 GMT on 21^st.

Fog (visibility < 1000 metres @ 0900 GMT) was observed on 3 days (2^nd, 6^th and 29^th) in November. Visibility fell below the 200 metres threshold at 0900 GMT on 2^nd.

AUTUMN (September/ November) 2008: The mean daily maximum temperature in Autumn was 14.1 C (-0.3), the mean night minimum temperature was 7.6°C (-0.3), total rainfall was 161.0 millimetres (97%), and sunshine was 341.7 hours (105%). The quoted mean daily maximum temperature was 3.0°C below the equivalent value in the very mild Autumn of 2006. Despite the mean temperature being only 0.3°C below average it was the coldest Autumn since 1998.

Met. Observer, Royston (Iceni) Weather Station

4^th December 2008

Return to Daily Weather Observations - November 2008 header page