There was a lot of talk in the media last year about the summers heat wave (2018) and comparisons with 1976. Here is a table of the top thirty warmest seven day periods since 1772 that I have extracted from the daily Central England Temperature [CET] series maintained by the Met Office that helps put things into perspective (figure 1). I would normally not display temperature to the nearest hundredth of a degree, but it is useful when doing comparisons using ranking.
As you can see this summers heat wave ranked only 21st in a list where any overlapping periods have been filtered out. If you consider a longer 30 day period, but this time using the daily maximum series that began in 1878 (figure 2), you will notice that 2018 figures more prominently than it did in the table of highest 7 day mean temperature, lying 3rd behind 1995 and 1976.
Finally, a table of the warmest 30 days using the mean temperature series (figure 3) does of course contain some new additions to the ones in the article that appeared in 1984, interestingly too, temperatures look slightly higher using the latest data. For example the mean temperature for the period 22 June to the 21 July in 1976 was 19.8°C compared to the 20.37°C it is now. All that can be assumed is that the series has been corrected slightly or adjusted in some way to allow for urbanisation. In this table 1976 is fractionally warmer than 1995 and 2018 is 6th warmest since 1772, again any overlapping periods have been filtered out. So summer 2018 was hot, but not quite as hot as 1976 or 1995, of course summer 2018 is not over yet, and could provide another surprise before it finally is.
For your information, anomalies in each of the tables are calculated with respect to the 1961-2010 long-term average.
(1) Storey, A.M & Folland, C.K. Hot summers in Central England and Central England Temperatures. Weather, 39(9), pp. 287-289