The wettest June in the EWP series that started in 1766 was that of 2012 with 160.1 mm of rainfall which was over 245% of the 1961-1990 LTA. It was wet across the entire country, but slightly less so over East Anglia. The EWP series is based on average rainfall totals across a grid of locations across England and Wales and because rainfall everywhere was close to twice the average the areal average was so very high.
The Met Office have kindly produced a graphic of just how wet the first 13 days of June (2019) have been. The anomalies in this chart are with respect to the LTA for the whole month. As you can see although it’s has been wet across NE Wales and particularly across the south of Lincolnshire and around the Wash, the rest of the country have been close to the monthly average, but because this is a crazy kind of anomaly chart these anomalies can and will only increase with the more rain that falls during the remainder of the month.
There is already talk about June 2019 being the wettest on record. This is slightly premature at the moment because we are not even half way through the month yet – but who knows.