In August 2025, over 200 fires burned the northwest of the Iberian Peninsula and released over one million tonnes of carbon monoxide. We used satellite measurements over 15 of those wildfires , covering 70 % of the area burned, to estimate emissions of carbon monoxide and smoke composition. Satellite-based estimates were about three times higher than common fire-emission datasets, highlighting the value and complexity of tracking major wildfires from space and the limits of current inventories.