Figure 1 final freeze season temperature anomaly, the entire Arctic Ocean had a positive temperature anomaly much of it exceeding +5 C, South of CAA had a final burst very cold March April but over all had seasonal temperatures.
Figure 2, Note high pressure zone projected exactly where it happened over NW Europe For April and May 2018.
Figure 3, NW Europe had a bit of a shiver...
Figure 4, the coldest air in the Northern Hemisphere for June 2018 was centred Just North of Ellesmere Island.
Figure 5, Arctic Ocean surface air temperature anomaly March 15 to April 30 very positive despite claims otherwise.