What is dirty brownish melting snow in the streets?

Dirty brownish melting snow in the streets typically consists of snow that has accumulated dirt, debris, and pollutants as it melts. This discoloration occurs due to the interaction of snow with the urban environment, where it picks up contaminants from the ground, vehicles, and litter. As temperatures rise and snow begins to melt, these impurities become more visible, creating a slushy, unattractive mixture. This phenomenon is common in city areas during winter and early spring.