What is the urban heat island effect?

• A. Cooler temperatures in cities.
• B. Increased rainfall only.
• C. No wind changes.
• D. Urban areas are warmer than surrounding rural areas.

Answer: (D)

Urban heat island effect means cities are warmer than surrounding rural areas, especially at night. Built surfaces like concrete and asphalt soak up and store heat during the day and release it slowly after sunset, while less vegetation means reduced cooling from evapotranspiration. The dense urban fabric also traps heat and often slows or redirects winds, so heat isn’t removed as efficiently. Add in extra heat from cars, industries, and appliances, and the temperature difference becomes even more noticeable. So the defining idea is that urban areas stay warmer than their rural surroundings. The other ideas don’t fit because they suggest cooler cities, rainfall becoming the only change, or no wind changes, none of which describe the main effect.