Smoke from Record-Breaking Wildfires in Spain and France

Extremely hot and dry conditions were prevalent across Europe and North America during June and July, which primed the land surface for dangerous wildfire conditions, in addition to the vast societal impacts from heat waves. Wildfires emit thick blankets of smoke containing toxic gases and fine particulate matter (PM_2.5). PM_2.5 aerosols are small enough to penetrate the lungs and enter the blood stream, thereby inducing and exacerbating pulmonary and cardiovascular health impacts. Though concentrations of PM_2.5 are highest close to the wildfire source, smoke can travel thousands of miles to impact the air quality elsewhere. Although research has demonstrated that the overall number of wildfires has been decreasing globally, wildfires are becoming more intense in North America and Europe.

Models such as the Goddard Earth Observing System (GEOS), which blend meteorological observations with a numerical weather prediction model, are valuable tools for understanding and predicting where wildfire smoke will travel. The wildfire smoke intensity visualization uses the aerosol optical depth (AOD) from brown carbon within a high-resolution version of the GEOS model to demonstrate the local and remote impacts of smoke over Europe in late July 2026. AOD provides an indication of how much smoke is in the air. A brown color in the visualization indicates high values of AOD, and therefore denser plumes of smoke.

The western European region had already experienced intrusions of Saharan dust in late June, which reduced air quality and gave the skies a reddish hue. As seen in the visualization, smoke from Canadian wildfires reached Europe but unprecedented wildfires in Spain and France generated dense plumes of smoke with profound impacts on air quality within the region. Complementing this broad view of smoke transport, two additional visualizations highlight the ground-level impact by tracking the progression of active fire perimeters. Using data from the NASA Fire Event Data Suite (FEDS) these focus specifically on the rapid expansion of the severe blazes near Madrid, Spain, and Bordeaux, France. There were also notable wildfires along the northern coast of Algeria in response to the same weather conditions that impacted Europe. These fires further increased the amount of smoke over the Mediterranean.