Florange, nestled in the Grand Est region of France, occupies a geographically significant position within the Lorraine historical province, bordering Luxembourg. Its coordinates (49.3222, 6.1192) place it within a gently undulating terrain, part of the broader Lorraine Plateau, characterized by rolling hills and valleys carved by ancient fluvial activity. The city sits at an elevation of approximately 280 meters above sea level, influencing local weather patterns and air circulation. Historically, Florange’s development is intrinsically linked to the iron and steel industry, forming a crucial node within the wider Moselle industrial belt, a legacy of extensive coalfields that once dominated the region. This industrial heritage continues to shape the urban landscape, with remnants of former mining operations visible in the surrounding areas. The urban–rural gradient transitions relatively quickly; beyond the immediate built environment, the landscape shifts to agricultural fields and woodlands, typical of the Lorraine countryside. The proximity to the Chiers River, though not directly adjacent to Florange, influences local humidity and can contribute to fog formation under certain meteorological conditions. The surrounding landscape, a mix of cultivated land and forested areas, plays a role in filtering pollutants, though the persistent industrial activity and the broader regional air quality challenges impact Florange’s atmospheric conditions. The valley setting can also trap pollutants, particularly during periods of low wind speed, exacerbating local air quality issues.

Florange’s air quality experiences a distinct seasonal cycle heavily influenced by meteorological factors. Winter months (December-February) often present the most challenging conditions. Cold temperatures frequently lead to temperature inversions, where a layer of warm air traps cooler air near the ground, preventing the vertical dispersion of pollutants released from industrial sources and residential heating. Fog, common during these months due to the Chiers River’s influence and the valley topography, further concentrates particulate matter. Spring (March-May) brings a gradual improvement as temperatures rise and wind speeds increase, aiding in pollutant dispersal. However, agricultural activities, including fertilizer application, can contribute to ammonia emissions. Summer (June-August) generally sees the best air quality, with consistent winds and higher temperatures promoting efficient ventilation. Occasional heatwaves can, however, lead to stagnant air conditions. Autumn (September-November) marks a transitional period, with decreasing temperatures and increasing humidity. Leaf fall can also contribute to particulate matter, and the return of temperature inversions in late autumn mirrors the winter pattern. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during winter and early spring, limiting prolonged outdoor exposure on days with low visibility or stagnant air. During the warmer months, while generally better, monitoring local conditions and avoiding strenuous activity during peak heat is advisable. The interplay of industrial emissions, agricultural practices, and regional weather systems dictates the fluctuating air quality throughout the year.