A grey and wet December day in Epping High Street (Photo: Roger Emmens)
The influence of Global Warming is clear
A review of the weather in Epping in 2020
Our automatic weather station was installed in Epping in December 2019, so now we have our first full year of data to mull over. Even better, since there was an operational weather station during the period 1979-2013, we now have 35 years of data to analyse trends and extremes. So some interesting conclusions can be drawn.
We’ve had some glitches to iron out in our first year of operation. Firstly, severe thunderstorms in August flooded the building in which the station monitoring equipment was running, and knocked out the power supply for three days. So we lost data on some significant rain events. Then in October a rain gauge malfunction was suspected when more severe rain fell over several days and seemed to be under-recorded: this time it transpired there was a slug in the rain gauge, presumably exhausted from such a climb but very clean! This is likely to have resulted in one of the most dramatic rainfall events in our history being missed. But more of that shortly.
So what of the weather in 2020?
Well, comparison of the data in our 35 year record shows that 2020 had a record high mean temperature, at 11.5 °C, approximately 1.1 °C above the average. It was also our sixth wettest year.
Looking at the month by month data, we had some notable firsts.
January was the warmest on record.
February was the fourth warmest.
April was the third warmest.
May was the warmest and also the second driest.
June was the fourth warmest.
July set a new record for the hottest July day, at 36.0°C.
In August, we had our seventh and eighth ‘tropical nights’ – nights where the temperature never fell below 20°C, and the first time in our records that this happened on two consecutive nights. The early heat broke with a cataclysmic series of thunderstorms, one of which was the one to take out our power supply – suffice it to say that at the point the power failed, the weather station was recording a rain rate of 109.8mm (about four inches) per hour! The power was out for three very wet days – anecdotal evidence, and data from nearby weather stations, suggests that if we had been able to record it, we would have seen that this August was indeed our wettest ever. Finally, as there was also a bit of unseasonably cool weather for a couple of days, August gave us our record temperature range between highest and lowest measurements across the month, of an amazing 28.6°C.
September set a new record for the hottest September day, at 31.2°C.
October was not just our wettest October, but our wettest month on record – despite under-recording thanks to that slug! It was also the only month in the year with a mean temperature that was (just) cooler than the long term average.
November then resumed the trend, being our third warmest, and unusually without any frosts recorded.
Finally, December was our third wettest, and temperatures above the long term average despite eight nights of frost. It also gave us our maximum wind gust of the year, at 44mph – that’s Gale Force 8 on the Beaufort scale – thanks to Storm Bella.
One last record: in January, in common with much of the UK, we recorded our highest ever barometric pressure, at 1049.3 hPa (millibars in ‘old money’).
So all in all, a fairly dramatic weather scene in 2020! It will be interesting to see if the extremes continue in 2021.
The source data for all of this can be made available to any school or other organisation or individual who wants to analyse it. We are also looking for anyone who would like to take on writing the monthly summaries, whether on a one off or continual basis, or who would like to submit a photograph representative of the month’s weather for our relevant Weather News post. Please contact us here.