The freely available gridded data series for precipitation by the Met Office has now been extended back to 1862, so I thought I would take a closer look at it by means of a 12 month moving average of rainfall and linear trend to see if the climate of the UK has become any wetter during that time. The chart below shows the full series back to 1862 and the numerous wet and dry spells that have occurred during that time. The only thing I can spot with any certainty at this range is the severe drought of 1975 and 1976. The linear trend shows the UK very gradually getting wetter in the last 157 years but not significantly (+4.4 mm/decade).
The chart below is of the last thirty years precipitation in the UK and you’ll notice that the linear trend is a little steeper. In the last thirty years the UK has got progressively wetter (+14.5 mm/decade) over time, whether this is due to global warming or not, I’ll let you decide. This graph has numerous peaks and troughs along in it, the three peaks between 2012 and 2016 look intriguing, and if you squint your eyes up it’s almost possible to imagine some kind of seven year cycle going on.