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Imus, the capital city of Cavite province in the Philippines, occupies a strategic position within the rapidly urbanising landscape of Southern Luzon. Situated approximately 20 kilometres southwest of Manila, Imus lies within the greater Manila metropolitan area, placing it at the heart of one of Southeast Asia's most densely populated regions. The city's terrain is predominantly flat lowland, typical of the Cavite coastal plain, with elevations averaging around 20-30 metres above sea level, though it gently slopes toward Manila Bay to the northeast. This proximity to Manila Bay—about 15 kilometres away—creates a complex air quality dynamic, as sea breezes can sometimes disperse pollutants but also transport marine aerosols and urban emissions from Metro Manila. Imus sits within Cavite's industrial corridor, surrounded by manufacturing zones in nearby General Trias and Dasmariñas, while retaining agricultural pockets in its periphery, creating an urban-rural gradient that influences pollution patterns. The city's location along major transportation arteries like the Aguinaldo Highway and Cavite Expressway means it experiences significant vehicular emissions from both local traffic and regional transit. Being part of the CALABARZON industrial belt, Imus receives transported pollutants from neighbouring industrial centres, while its own urban development contributes localised emissions from construction, transportation, and commercial activities. The flat topography limits natural ventilation, allowing pollutants to accumulate, especially during periods of atmospheric stability.

Imus experiences a tropical monsoon climate with distinct wet and dry seasons that shape its air quality patterns throughout the year. During the dry season from November to April, particularly from January to March, pollution typically peaks due to reduced rainfall, increased atmospheric stability, and frequent temperature inversions that trap pollutants near the surface. These months often see higher concentrations of particulate matter from vehicle emissions, construction dust, and industrial activities, making them less favourable for outdoor exercise, especially for sensitive groups like children, the elderly, and those with respiratory conditions. The northeast monsoon (Amihan) from November to February brings cooler, drier air that can sometimes disperse pollutants but also carries haze from regional agricultural burning. From May to October, the southwest monsoon (Habagat) dominates, bringing heavy rainfall that significantly improves air quality by washing pollutants from the atmosphere. June to September offers the cleanest air, though occasional stagnant conditions before thunderstorms can cause short-term pollution buildup. The transition months of May and October see variable conditions as monsoon patterns shift. Sensitive individuals should monitor local air quality reports during the dry season peak, limit strenuous outdoor activities on visibly hazy days, and consider indoor air purification during prolonged dry spells. The lack of extreme weather hazards means pollution remains the primary air quality concern across all seasons.