This paper provides a rare and comprehensive observational assessment of the spectral radiative effects of extreme wildfire aerosols using high-quality, ground-based measurements. The study combines sun-photometric observations, spectral irradiance measurements, radiative transfer modelling, and in situ aerosol and trace-gas data to quantify aerosol radiative forcing under near-source conditions. Such detailed spectral analyses are scarce and directly relevant to atmospheric radiation, aerosol–climate interactions, model evaluation, and the interpretation of long-term aerosol and radiation datasets. The manuscript may also be of interest to the broader public and media, as it documents the atmospheric and radiative impacts of an extreme wildfire event that occurred in close proximity to populated areas. Wildfires are increasingly frequent and intense under climate change, and the study provides a tangible, observation-based illustration of how wildfire smoke can dramatically reduce surface solar radiation, alter atmospheric composition, and affect regional energy budgets. The use of real measurements during a well-documented extreme event makes the results accessible and relevant beyond the specialist community, particularly in the context of climate change impacts, air quality, and extreme events.