Averages and extremes
Essex is the driest county in the UK. The driest spot of all is St Osyth, with a mere 513mm per annum on average. Whilst Epping's average is quite a bit more at 679mm, this is still drier than most places in the UK.
Here are the monthly averages based on the Woodberry Down station over 1979-2013:
The wettest year on record was 2000 with 974mm, and the driest was 1983 with 457mm.
On average, it rains on 182 days of the year. In 2012 it rained on 219 days, wherease in 1990 it rained on just 130 days. It has never rained on every day of the month, although in April 1998 it rained on 28 days. Similarly we have never had a completely dry month, although in May 1990 and April 2011 it rained on just 2 days. The longest dry period was from 11th November to 11th December 1989, thirty days without any rain.
The wettest month recorded was October 2000 with 162mm, and the driest was May 1989 with just 1.3mm.
The wettest day on record was 29th July 1987 with a biblical 59.0mm, or more than 2.3 inches.
Epping is in the warmest region of the UK in summer, and one of the coolest for its altitude in winter.
The average daily maximum varies from 6.6°C in January to 22.6°C in July, whilst the average daily minimum is from 1.8°C in January to 12.9°C in both July and August.
The graph below shows how these temperatures vary through the year, based on the data period 1979-2013, and also shows the hottest and coldest temperature recorded in the month during 1979-2013 and 2020 to date.
The hottest temperature on record was 38.8°C on both 18th and 19th July 2022. A heatwave in July 2006 recorded the highest number of days where the temperature peaked over 30°C, with ten, including six days in a row; six successive days was also recorded in August 2020.
When it comes to "tropical nights", which are nights where the temperature never dips below 20°C, we have recorded just nine: in July 1983, August 1990, August 1993, July 1994, August 2004, July 2006, two successive nights in August 2020, and July 2022. The warmest of these was the last, when overnight on 18th to 19th the minimum temperature recorded was 23.0°C.
The coldest temperature recorded was -10°C on each of 1st January 1979 and 12th,13th,14th January 1987 (at that time temperature was recorded to half a degree rather than the tenth recorded latterly). The 12th January 1987 was also our coldest ever day, when the temperature never rose above -8°C. We have recorded several such "ice days" where the temperature never rises above freezing, and three times we have recorded eight ice days in a month: in December 1981, February 1986, and December 2010. The longest continuous run of ice days was in February 1985, when we recorded seven successive freezing days.
Our earliest recorded frost (air temperature below zero) was on 16th October 1993 (-1.0°C), and our latest recorded frost was on 12th May 2010 (-0.6°C). There have doubtless been several earlier or later ground frosts giving hoar on grass or ice on car windscreens, but these can occur with the air temperature as high as 3°C.
Records only cover 2003-2013 and since 2020, but the highest pressure of 1049.3 hPa (hectopascals are also referred to as millibars, or mb) on 19th January 2020 came at the time of the highest ever recorded pressure for UK of just over 1050 in Cornwall, so it is a pretty good assumption that this is our record air pressure. At the other end of the scale, our lowest recorded barometer reading was 968.2 hPa on 10th March 2008.
Photo: The Green in a snowy January 2010