Foggy May, rather rainy and colder than usual, said goodbye to us in spring more variable than its usual variability. how much summer what starts, his first steps seem cool, no rain.

May 2023 was the coldest month in the country in terms of climate indicators. Yes, I like it notes Stavros Dafis in “K”., a researcher at the Athens National Observatory, it was “the coldest May since 2010 for the eastern mainland and northern Greece”. According to the first data processed by the Observatory, in most regions of the country, the average monthly temperatures were lower than the climatic values ​​of previous years. “In fact, the deviation in Macedonia, Thessaly and Central Greece was particularly significant as it was about 2.5 degrees Celsius below normal temperatures for this season,” – says Costas Laguvardos “K”.director of research at the Athens Observatory and scientific director of meteo.gr.

A particular sensation this year was caused by the number rainy days. “It rained for half of May in many parts of the country. It was not so much the amount of water that fell, but the frequency and constant repetition of rainy days, even with a little rain, ”says Mr. Laguvardos. “Northern Greece, the Dodecanese and Crete had a lot of rainfall,” notes Mr. Dafis, “while it was close to average in the rest of the regions. The most special thing about this year was that more than half of the days were rainy.” The phenomena were more intense in the eastern country and northern Greece, while in western Greece both temperature and precipitation were very close to the average.

“Let it always rain. In previous years, we met May with heavy rainfall in 2018, 2012, 2011. This is not unusual, maybe this year we had many days with rainy weather,” adds the director of research observatories.

In fact, as Mr. Dafis points out in a post on meteo.gr, “Spring rains this year are not unprecedented in intensity and duration. In May 2018, for example, monthly rainfall at many weather stations at the National Observatory of Athens was 200% above normal for the season.”

“May is characterized by instability, heavy rains, storms, lightning, weather fluctuations, etc.,” emphasizes Mr. Laguvardos, recalling that there have always been deaths due to lightning in the last month of spring. And this year in May, there was no shortage of storms and lightning, and there was even one person killed by lightning in Rhodes on Monday – a young tourist who was at sea. The foggy weather in May also played a role in the transport of African dust, as is often the case this month.

According to short-term forecasts, the first half of June is also expected to be rainy and cool.

“May is the second month after April when the temperature is below normal and there is more rainfall. However, before that there was a long period, from September to March in most regions, when the opposite trends were recorded: warmer and drier months,” comments Mr. Laguvardos.

OUR Weather instability in May it is not only a Greek phenomenon. Torrential rains and floods have hit Spain since the second half of last month, ending a long drought that has killed 14 people. Italy also endured heavy rains and storms that caused floods that killed 18 people in May. May was also rainy in Turkey.

“The peculiarity of Greece was that it was a cold corner of Europe, as in other Mediterranean countries the temperature approached the usual levels for the season,” notes Mr. Dafis.

root cause

What are the reasons for these phenomena? “The main reason for the long-term instability of the atmosphere over our region this year is the presence of very high atmospheric pressure in northern Europe. Unusual for the season very low temperatures and deep depressions north of Europe, in the Arctic, contributed to the formation of anticyclones in northern Europe, which prevented the usual movement of barometric lows from the Atlantic to Central Europe,” explains Mr. Dafis.

“Combined with a strong air current in southern Europe, this atmospheric circulation over our region has “trapped” cold and unstable air masses, which has led to long-term instability in our country and in general in the Mediterranean countries. It is predicted that such an atmospheric picture will continue at least during the first week of June.”

According to short-term as well as seasonal forecasts, the first half of June will have wetter and cooler weather compared to climate values. Maybe this summer is a little late to start.