Global solar energy resources were redistributed in the first half of 2026 as blocking patterns early in the year and the disruption of the Northern Hemisphere’s polar vortex gave way to the development of El Niño conditions from April onwards, analysis using the Solcast API. Much of Europe, the United States, Southeast Asia, South America, and Central Africa had irradiance 5 to 10% above the long-term average, while most of Canada, Mexico, South Africa, North Africa, parts of western Russia, and Central Asia were 5 to 10% below average.
Most of Europe saw significantly more solar energy than normal in the first half of 2026. The pattern began in winter, when cold, dry air reduced cloud cover in parts of eastern and northern Europe, increasing insolation even as storm systems reduced solar energy sources further west. Spring strengthened the surplus. In April, persistent high pressure over the North Sea kept skies clearer in western and northern Europe, with France 13% above the 2007-2025 baseline, Germany 11% above average and Finland 16% above normal. May continued this pattern as clear skies stretched from Spain to Ukraine, with the strongest anomalies around Austria, where insolation reached as much as 25% above normal. For solar energy production, the practical impact consisted of longer periods of higher irradiation in several major European markets, despite local reductions at the edges of the weather systems.
Saharan dust is a recurring feature of Europe’s solar resource, with multiple events per year reducing insolation and increasing pollution in affected areas. Below, an example from March shows such a dust transport event, where material is transported from North Africa across Europe, reducing the solar energy source.
Solar performance in North America has been more varied. The United States experienced repeated periods of above-average insolation throughout the winter and early spring, after the late January storm disturbance gave way to brighter conditions over much of the central, eastern, southern and western US. The pattern changed in the second quarter. Western and domestic markets remained near or above average, while Texas and the Gulf Coast trended negatively as moisture, clouds and rainfall reduced insolation. California’s Central Valley also recorded below-average insolation, where persistent tule fog suppressed solar sources for extended periods, as seen in the maps below. The seasonal shift in North American insolation becomes apparent when comparing the first and second quarters. Broader gains across much of the United States in winter and early spring gave way to a more regional pattern beginning in April, with clearer contrasts among inland regions and reduced insolation in the South, mainly impacting Texas and ERCOT solar production.
South America showed in January how wildfire smoke can reduce solar energy resources, even as broader conditions are otherwise clear. In northern regions, insolation fell by up to 15% as rainfall and storm activity increased cloud cover. Further south, warmer and drier conditions in northern Argentina and central Chile reduced cloud formation and increased radiation in some areas, but wildfire smoke reduced available sunlight during otherwise brighter periods. For solar sites, this meant that clear sky conditions did not always translate into the same gains in surface radiation.
The Asia pattern in the first half of the year did not follow a single regional split, but instead shifted between northern and southern markets as cloud and rain patterns changed. South and
China’s coastal areas started strong in January and February as reduced cloud cover and lower aerosol levels improved insolation, with Hong Kong more than 25% above average in January and parts of southern China and Taiwan remaining above average in February.
In April, the strongest gains shifted south to mainland Southeast Asia, where clearer, drier conditions eliminated radiation and Bangkok recorded its sunniest April since 2007. At the same time, persistent cloud cover and rainfall reduced radiation irradiance across eastern China, with the Yangtze Delta approximately 10% below average.
By May, the contrast had shifted again, with stronger radiation returning to parts of coastal East Asia, while cloud cover and rainfall reduced solar resources elsewhere in the country.
region.
The May snapshot shows how neighboring markets recorded very different irradiation results under these cloud and rain patterns.
Australia showed a clear contrast between central and coastal areas during the first half, with below-average insolation across central Australia and stronger sunshine along parts of the east and west coasts. Repeated cloud and rainfall induced by cyclones suppressed inland insolation, while coastal areas experienced more frequent clear spells.
January was largely above average, but monsoon clouds and Tropical Cyclone Koji reduced insolation in the tropical north. Cyclone Mitchell contributed to Australia’s wettest February since 2011, causing 15-30% radiation intensity deficits in the central and eastern regions, before Cyclone Narelle brought clouds, rain and dust.
Queensland, the Northern Territory and Western Australia in March. Cyclone Malia later limited the increase in irradiance in April in Far North Queensland and the Northern Territory. For solar operators in the affected inland and northern regions, the pattern meant more variable irradiance, a higher risk of dust pollution and more challenging site conditions during periods of heavy rain and cyclone activity, while coastal areas in parts of the east and west saw stronger resources.
In the first half of 2026, Europe experienced broad increases in irradiance, while the United States remained above average overall, despite more localized disruptions in Texas, the Gulf Coast, and parts of California. Asia, South America and Australia showed more regional variability, caused by cloud cover, rainfall, dust, smoke and tropical systems. From April,
The development of El Niño conditions added a new layer by reshaping rainfall and cloud cover in Asia and Australia.
Solcast produces these figures by tracking clouds and aerosols worldwide at a resolution of 1-2 km, using proprietary satellite data AI/ML algorithms. This data is used to drive irradiance models, allowing Solcast to calculate high-resolution irradiance, with a typical deviation of less than 2%, as well as cloud tracking predictions. This data is used by more than 350 companies that manage more than 300 GW of solar energy worldwide.
