Final answer:
The phenomenon described is the urban heat island effect, where cities have hotter summers and milder winters compared to surrounding areas.
Step-by-step explanation:
The phenomenon described in the question is known as the urban heat island effect. This effect occurs when urban areas experience higher temperatures compared to the surrounding rural areas. In Atlanta, the presence of concrete and asphalt in the city retains heat, leading to hotter summers. In contrast, the surrounding areas with more open spaces and vegetation have a milder climate during winters.
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