Per-Ola Olsson

Rapid urban growth is making cities hotter, a trend further exacerbated by climate change. Urban green spaces (UGS) are commonly used as nature-based solutions to reduce heat, but there are gaps in understanding how cooling effects vary across climate zones. Using satellite data from 2021 to 2024, we examined urban heat and UGS patterns during the hot season across four Ethiopian cities with different sizes, topographies, and climates. UGS expanded more exposed to heat. Daytime surface temperatures decreased in all cities, indicating UGS-related cooling, while nighttime temperatures showed more mixed results. UGS had a strong cooling effect in Addis Ababa and Jimma (R² = 0.53–0.77; p < 0.001), moderate effects in Adama (R² = 0.24–0.42; p < 0.05), and little effect in Harar (R² ≤ 0.07; p > 0.05). This demonstrates that UGS influences heat differently depending on local climate and land cover. Heat hotspots were linked to impervious surfaces, urban agriculture, and soil moisture differences rather than UGS alone. Heatwave patterns also differed: Addis Ababa and Jimma experienced longer but less intense heatwaves, while Adama and Harar experienced shorter but more intense heatwaves. Overall, the results highlight the need for city-specific greening and surface-cover strategies to reduce heat risks and promote climate-resilient urban growth in Ethiopia and other regions experiencing rapid warming.