2021 Summer was a very hot one, according to analysis by METEO. In the June-August quarter, the average temperature in Greece exceeded two degrees Celsius in several areas. Overall, positive temperature deviations have dominated most of the northern hemisphere this year, with the largest deviations found in the western United States, the Mediterranean, Siberia and the western parts of Russia. The analysis shows that the 2021 summer in Greece was the hottest in the last 43 years, followed by those of 2007, 1987, 2000 and 2012. These results are related to the most extreme heat episodes that occurred during these summers. Analysing the five most hottest heat waves, it appears that the heat wave between July 27 and August 6 this year, had the longest duration (188 hours), followed by those of June 2007, July 1987, July 2007 and June 2021. Also, the heat wave between July 27 and August 6, 2021, along with that of June 2007, had the greater intensity, followed by those of 1987, July 2007 and June 2021. READ MORE: New Algorithm Tool to Predict, Prevent Floods in Greece.