Exceptional June sunshine in England and France as summertime high pressure moves northward

Unusual high pressure over the North Sea caused June's total irradiation across England and France to be as much as 20% above normal, according to data collected by Solcast, a DNV company, via its Solcast API.

In early summer, a ridge of high pressure known as the “Azores High” usually sits over the North Atlantic Ocean. This June, the high pressure extended much further northeast than usual, and was centered over the North Sea, and was weaker than usual over the North Atlantic.

The persistent high pressure over the North Sea brought drier easterly winds to large areas of western Europe, whilst also limiting the passage of cloud-bearing weather systems from the Atlantic. This pattern delivered a sunshine excess of up to 20% above normal over England and France, and a smaller excess of around 5-10% above normal for Italy, Switzerland, northern Spain, and western Germany.

Central and eastern Europe and southern Spain were also affected by this weather pattern. However, their irradiance boost was dampened by local convective and storm outbreaks, resulting in their overall irradiance being close to normal.

When looking at the absolute total irradiance for June, the result was that France experienced about the same total irradiance as the typically sunnier Spain and Italy, whilst irradiance totals were lower over central and eastern Europe and Scandinavia.

Solcast produces these figures by tracking clouds and aerosols at 1-2km resolution globally, using satellite data and proprietary AI/ML algorithms. This data is used to drive irradiance models, enabling Solcast to calculate irradiance at high resolution, with typical bias of less than 2%, and also cloud-tracking forecasts. This data is used by more than 300 companies managing over 150GW of solar assets globally.