Where have I said they were the average temperatures? Please don't try and put words in my mouth. I quoted common peak early afternoon temperatures in early August, when the 2°C and the 20% RH differential is usual between inland and the coast. I did not quote absolute peaks, either, but a real peak that will occur on at least 2 or 3 days each year, usually about 7 - 10 days.
If you care to Google "temperature humidity comfort", you will obtain many thousand results, some of which will discuss this problem with charts. In fact, with the figures I mentioned, the coastal conditions exceed the sunstroke threshold on some of the comfort charts while the inland ones don't. This is not subjective but studies by scientists over more than 75 years.
You can also ask the EAC, who will tell you that the per capita consumption of electricity in the coastal towns is about 20% higher at peak summer conditions than inland. This is, of course, because of the need for higher levels of aircon. The same applies to California, where the peak demand exceeded the supply a few years ago: the rolling blackouts that were applied were to the coastal towns, because that is where the overloading was greatest.