Summer Extremes Outlook

Extremely high temperatures can occur during the summer period. Climate forecasts for up to 4 weeks ahead, known as sub-seasonal forecasts, can provide an insight into the conditions for the coming weeks and help predict extreme weather events, such as a prolonged period (several days) of abnormally hot temperatures or heatwave.

Extreme temperatures can cause a peak in electricity demand due to increased use of cooling systems. Within the framework of the S2S4E project, an outlook of the sub-seasonal forecasts will be issued weekly for 1-4 weeks ahead, which can be used to anticipate these summer extremes. These forecasts will be made available every Friday on this page.

A detailed explanation of how these forecasts can be interpreted, and a use case of how sub-seasonal forecasts predicted the heatwaves in summer 2019 are provided in the Summer Extremes factsheet.

Summer Extremes Factsheet

Sub-seasonal and seasonal forecasts for other regions, variables and forecast windows are available in the S2S4E Decision Support Tool.

 

Outlook - 18 September 2020

Sub-seasonal forecasts issued on the 17th of September predict that unusually high temperatures for the season are expected throughout most of central and eastern Europe, and the Mediterranean Sea during the week of 21-27 September, with a risk of high extremes. By contrast, below normal temperature are likely to be seen in the Iberian Peninsula, the UK and the western coast of Norway. These temperature patterns are likely to persist in the week 28 September to 4 October, however high extremes are only expected around the Black Sea and eastern Mediterranean, particularly in Cyprus and southern Turkey. Forecasts for 3 and 4 weeks ahead do not show any strong signals of extremes, although temperatures above normal might persist in eastern Mediterranean.

18 september

Outlook - 11 September 2020

Sub-seasonal forecasts issued on the 10th of September predict exceptionally high temperatures with a risk of extremes throughout Europe, except for Portugal and western Spain, for the week of 14-20 September. High temperatures are likely to persist the following week (21-27 September) in central and eastern Mediterranean, particularly in Italy, parts of Greece, and Cyprus. By contrast, the Iberian Peninsula might see below normal temperatures until the end of September. Forecasts for 3 and 4 weeks ahead show no strong signals of extremes, although temperatures above the normal conditions for the season might persist in parts of the Mediterranean.

subseasonal 10 september

Outlook - 4 September 2020

Sub-seasonal forecasts issued on the 3rd of September for 1 week ahead indicate that exceptionally high temperatures are likely to affect the greatest part of eastern Europe, eastern Mediterranean, the Balkan Peninsula, and the Black Sea. Lower than usual temperatures for the season are likely to occur in Iceland and the North Sea region. 

High temperatures with a risk of extremes are expected to persist in eastern Europe the following week, from 14 to 20 September. By contrast, most regions of central and western Europe are predicted to experience below normal temperatures this week.

Forecasts for 3 and 4 weeks ahead show no strong signals of extremes, but temperatures are likely to continue to be above normal in eastern Mediterranean and the Red Sea. 

Summer extremes outlook 3 Sept

Outlook - 28 August 2020

Forecasts issued on the 27th of August predict a risk of high temperature extremes during the first week of September in the greatest part of eastern Europe, eastern Mediterranean, the Balkan Peninsula, and the Black Sea. During this week, warmer than usual temperatures are expected in the Baltic Sea and the Atlantic, off the west coast of the Iberian Peninsula. Lower than usual temperatures for the season are likely to occur in western Mediterranean and more specifically in Italy, the south of France, and the west coast of Spain.

From the 7th to the 14th of September, the risk of high temperature extremes is likely to persist in eastern Mediterranean countries, the Red Sea, and the Black Sea. Warmer than usual temperatures are expected in the central and eastern Europe, the Baltic Sea and the north of Africa, while below normal temperatures are likely to occur in Ireland and the east coast of the UK.

Forecasts for the week 14th – 20th of September suggest that above normal temperatures are likely to persist in the eastern Mediterranean region, the Balkan Peninsula, and the Black Sea, with a risk of localised extremes.

Forecasts for the week 21st – 27th of September show some signals of heat extremes along the coast of Lebanon, Israel and Egypt, as well as in the Red Sea.

Forecasts issued on the 20th of August predict a risk of high temperature extremes during the last week of August (24th-30th) in the south of the Iberian Peninsula, North Africa and in the Atlantic off the west coast of the Iberian Peninsula. During this week also the Mediterranean basin will experience warmer than usual temperatures.

From the 31st August to the 6th September warmer than usual temperatures are expected in the Iberian Peninsula and Scandinavian countries, with some localised risk of high temperature extremes in the south of Spain and Northern Africa.   

For the week 7th-13th September higher than usual temperatures are expected towards the eastern Mediterranean Sea, which will persist the following week 14th-20th September. 

 

Summer extremes outlook 21 Aug

Forecasts for 1-4 weeks ahead, issued on the 13th of August, predict a risk of temperature extremes in the greatest part of north-eastern Europe, the Mediterranean Basin, North Africa and the Atlantic Ocean, between the 17th and the 23rd of August. The risk of unusually high temperatures will mainly affect southern Scandinavia, the Baltic countries, western UK and Ireland, the north of Poland and Germany, Belgium, and the Netherlands. In the Mediterranean Basin, exceptionally high temperatures are expected off the south coast of Italy, while unusually low temperatures for the season will be seen in the Aegean Sea.

Higher than usual temperatures are expected in eastern Europe, the Baltic Sea, western Mediterranean and the Atlantic during the last week of August, while the risk of heat extremes persists in the northeast of Africa. Forecasts for the first week of September suggest that above normal temperatures are likely to persist in the western Mediterranean, the Baltic Sea and the northeast of Africa, while no signals of extremes are seen. Forecasts for the week 7th – 13th of September suggest higher than usual temperatures in the Black Sea, with a risk of extremes.

 

14August forecast

Sub-seasonal forecasts issued on the 6th of August for 1 week ahead indicate that exceptionally high temperatures are likely to affect central and western Europe, particularly France, Germany, the UK, and parts of Italy, Spain and Norway, with a risk of extremes. For the week of 17 to 23 August, the forecast shows no clear signal of temperature extremes, although higher than normal temperatures are expected in the western Mediterranean and parts of Scandinavia. No clear signal is produced by the sub-seasonal forecasts for the week of 24 to 30 August. For the first week of September, forecasts predict above normal temperatures in central and eastern Europe, and Italy. 

Summer extremes outlook 7 Aug
Forecasts for 1-4 weeks ahead, issued on the 30th of July, predict a risk of temperature extremes in western Europe and western Mediterranean throughout most of August. Unusually high temperatures are expected in the first week of August (3-9 August) in southwestern Europe, particularly in the Iberian Peninsula and Canary Islands, as well as in parts of western Mediterranean. By contrast, below normal temperatures for the season will be seen in the Aegean Sea. In the week 10-16 August, high temperature with a risk of extremes are likely to persist in the Iberian Peninsula, Canary Islands and France, and parts of Italy, Belgium and Germany. Above normal temperatures might also affect parts of Scandinavia and the UK. Forecasts for 3 and 4 weeks ahead show that temperature extremes are expected in western Mediterranean until the end of August. No strong signals of extremes are seen in eastern Europe/Mediterranean in these forecasts.

 

Summer extremes forecast for 31 July 2020
Sub-seasonal forecasts for 1-4 weeks ahead, issued on the 23rd of July, predict exceptionally high temperatures throughout the Mediterranean for the week 27 July to 2 August. A risk of extremes is seen throughout the region, affecting Spain, southern France, Italy, the Balkans, Greece, Turkey and Cyprus. High temperatures with a risk of extremes are expected to persist in the Mediterranean the following week, from 3 to 9 August. By contrast, northern regions of Europe, including the UK and Scandinavia, are predicted to experience below normal temperatures in these first two weeks of forecasts. Forecasts for 3 and 4 weeks ahead show no strong signals of summer extremes, but temperatures are likely to continue to be above normal in the Mediterranean. 

 

24 July
Forecasts for 1-4 weeks ahead, issued on the 16th of July, predict above normal temperatures in parts of the Iberian Peninsula, the Black Sea and Turkey in the week 20-26 July. By contrast, a risk of low extremes is seen in northern Europe, particularly in the UK and Scandinavia, and parts of eastern Europe. High temperatures are likely to persist around the Black Sea and Turkey the following week (27 July to 2 August), while there are no strong signals of extremes throughout Europe. Forecasts for 3 and 4 weeks ahead show no strong signals of summer extremes, but above normal temperatures are expected in some parts of the Iberian Peninsula, France and Italy at the beginning of August.

 

Outlook for 17 July
Forecasts for 1-4 weeks ahead, issued on the 9th of July, predict exceptionally high temperatures in parts of France, the Iberian Peninsula and the Canary Islands for the week 13-19 July, with a risk of extremes. These high temperatures are likely to persist in the week 20-26 July. By contrast, unusually low temperatures for the season are expected in central and eastern Europe, and the eastern Mediterranean on 13-19 July. Forecasts for 3 and 4 weeks ahead show no clear signals of summer extremes at the end of July and beginning of August.

 

10 July Outlook
Forecasts issued on the 2nd of July for 1-4 weeks ahead show that unusually high temperatures are expected in parts of eastern Europe, the Black sea, the Iberian Peninsula and the Canary Islands for the week 6-12 July, with a risk of extremes. These high temperatures are likely to persist in Turkey, Bulgaria and the Black Sea for the following two weeks. Above normal temperatures are also likely to persist in the last two weeks of July in southeastern Mediterranean. By contrast, low extremes are predicted in the UK and North Sea region throughout the month of July.

 

3 July summer extremes forecasts
Forecasts for 1-4 weeks ahead, issued on the 25th of June, show exceptionally high temperatures in areas of southern Europe and north of Africa between the 29th of June and the 5th of July. The risk of high temperatures will mainly affect the south of the Iberian Peninsula, the north of Africa, the Canary Islands, the Balkan region, the Black Sea, and to less extent the Baltic Sea. 

 

Higher than usual temperatures are expected in the Iberian Peninsula and west France between the 6th and the 12nd of July, while the risk of heat extremes persists in the north of Africa and the Black Sea. During the week 13th -19th of  July, higher than usual temperatures are likely to affect the Mediterranean coast of Spain, the Canary Islands and southern Sweden and Norway. Forecasts for the week 20th -26th of July indicate that higher than usual temperatures are likely to persist in southern Scandinavia.  

26June_forecast

Forecasts for 1-4 weeks ahead, issued on the 18th of June, show that unusually high temperatures are expected across northern and central Europe between the 22 and 28 June. These temperature extremes will mainly affect the northern parts of France, Germany and Poland, and the UK, Scandinavia and Baltic countries. Temperatures above the normal conditions for the time of year are likely to be seen in parts of central, eastern and southwestern Europe in the week of 29 June to 5 July, although there is no clear signal of extremes. Forecasts for 3 and 4 weeks ahead do not show any clear signals of summer extremes, but indicate that high temperatures are likely to persist in the Canary Islands.

Forecasts 19 June

Forecasts for 1-4 weeks ahead, issued on the 11th of June, show that exceptionally high temperatures are expected in northern and eastern Europe for the week of 15-21 June. These temperature extremes will mainly affect Scandinavia, Baltic countries, the north of the UK, eastern regions of Europe and the Canary islands. Temperatures above the normal conditions for the time of year are likely to persist in parts of Scandinavia and the Baltics in the week of 22-28 June. Forecasts for 3 and 4 weeks ahead do not show any clear signals of summer extremes.  

12 June Outlook