Evaluation of the cooling effect of green and blue spaces on urban microclimate through numerical simulation: A case study of Iloilo River Esplanade, Philippines

•The cooling effect, heat reduction, and energy saving potential of Iloilo River Esplanade, Philippines was estimated.•ENVI-met software was utilized to simulate diurnal air temperature within the study site.•The estimated maximum cooling effect of the urban park during the hot dry season is 2.63°C which occurs during mid-afternoon.•Horizontal and vertical distance from the park, wind direction, and surrounding land cover contribute to the variation in cooling effect of the urban park. The aggravating impacts of the urban heat island phenomenon in Philippine cities has motivated planners to utilize urban green and blue spaces as a potential mitigation strategy. This study aims to assess the cooling effect (CE), heat reduction (HR), and energy saving potential (ESP) of trees and water along the Iloilo River Esplanade located in Iloilo City, Philippines. Microclimate modelling and simulation during summertime were performed using ENVI-met software and validated using field observations. Results of the study show that the urban park can provide a maximum CE of 2.63°C at 3:00 PM near the southern edge of the river, which is equivalent to a HR of 13,564 J and an ESP of 1.09 × 10−2 kWh. Meanwhile, a temperature increase of up to 0.16°C can be observed at night due to the nocturnal warming effect of water. In terms of spatial distribution, CE, HR, and ESP tend to gradually decrease as the horizontal distance from the park and altitude increases. Moreover, wind direction may also increase the scale and intensity of CE downwind, but it has an opposite effect in areas upwind.