Temporal variations of urban heat island intensity in three major cities, Thailand

Abstract

The mean maximum urban heat island (UHI) intensity in three major cities in Thailand was investigated by using data measured at two meteorological observatories (an urban site and rural site) in each study area for the period 2004 to 2008. Thermal contrasts between the urban and rural sites were positive which indicated that most of the time the air temperatures at the urban sites were higher than the air temperatures at the rural sites. The strongest mean maximum UHI intensity occurred in the nighttime and in the early morning, while the weakest mean maximum UHI intensity was reached during the daytime. The results indicated that UHI events occurred more frequently in the nighttime than in the daytime. Seasonal analyses showed the mean maximum UHI intensity was weakest in the rainy season (May-October) and was strongest in the dry season (November-April).