October was a disappointing Autumn month with temperatures and sunshine both below average, and rainfall above average.

Not only was it the coldest October since 2003, but it was also the 4^th month in the last 5 months with a below average mean temperature (August being the exception).

The mean daily maximum temperature in October was 13.7°C, which is 1.0°C below average. The mean night minimum temperature of 7.4°C was similarly below average, but by only 0.7°C. The highest temperature recorded in October was 17.5°C (on both 1^st and 2^nd) but this is not a particularly high value as it has been exceeded or equalled in October in all but 3 of the previous 40 years.

The lowest temperature in the month was 0.9°C on 27^th, whilst the lowest grass minimum temperature was –2.1°C on 28^th. A total of 4 ground frosts was recorded in October, but as the lowest temperature implies no air frosts occurred. In the previous 40 years air frost has occurred in October in only 7 years.

The mean earth temperature at 30 centimetres depth as recorded at 0900 GMT daily was 5.2°C, which is 0.4°C below average. The highest earth temperature recorded in the month was 13.5°C on 1^st, 2^nd and 3^rd, whilst the lowest earth temperature logged was 9.0°C on 31^st.

After the respite in August and September from the heavy rainfall in the April to July period, wet conditions returned again in October with a rainfall total of 85.6 millimetres, which is 137% of average. It was the wettest October since 2001.

The number of "rain days" (0.2 millimetres or more) in October was 22, with rainfall equalling or exceeding 1.0 millimetre on 14 of these days. Since 1972 only October 2000 has had a higher number of "rain days" and then only by a margin of 1. The wettest day in the month was 5^th with 15.3 millimetres rainfall, but 31^st was nearly as wet with 13.0 millimetres rainfall.

The cumulative total of rainfall for 2012 to the end of October was 667.5 millimetres, which is 135% of average.

For only the second time in the last 40 years snowfall occurred in October with a few flakes of snow in the morning of 27^th.

October could not match October last year for sunshine and the sunshine total of 109.3 hours this year was a sizeable 66.0 hours down on last year. It was the dullest October since 2009 only, however. The sunniest day of the month was 6^th with 9.4 hours sunshine. The only day of the month with no sunshine at all was 19^th and this was the first sunless day since 11^th June (129 days).

The mean wind speed in October was 5.7 mph, and the maximum wind gust recorded in the month was 39 mph on 16^th. The highest daily (00/00 GMT) mean wind speed was 11.5 mph on 16^th whilst the lowest daily mean wind speed was 1.5 mph on 10^th.

The analysis of wind directions as observed at 0900 GMT daily was NORTH 2 days, NE 3, E 1, SE 4, S 4, SW 7, W 7, NW 2 and CALM 1.

The mean MSL air pressure in October was 1009.1 mB, which is 4.7 mB below average. The highest and lowest pressure values recorded in the month were 1024.1 mB and 977.0 mB on 23^rd and 31^st respectively.

The mean relative humidity in the month was 89.4%, this value being enhanced by 3 foggy days from 22^nd to 24^th when the cloud base was at ground level for much of the time. The highest daily (00/00 GMT) mean relative humidity was 100.0% on 24^th, and the lowest daily mean relative humidity value was 77.3% on 16^th. The absolute lowest relative humidity reading in October was 52% at 1330 GMT on 3^rd.

Fog (visibility < 1000 metres @ 0900 GMT) was observed on 4 days in October (7^th, 22^nd, 23^rd and 24^th), with visibility on the latter 3 days falling below the 200 metres threshold.

Met. Observer, Royston (Iceni) Weather Station

5th October 2012