Northern and central coastal provinces will see highest temperatures at 35-38C on May 16, while in the central mountainous region the mercury is expected to reach nearly 40C. The hot weather is a result of the foehn effect, caused by a warm low-pressure in the west combined with southwest winds, stated the National Centre for Hydro-meteorological Forecasting. The heat is expected to become more intense from May 17-19 with highest temperatures at 36-39C across the northern and central regions. Temperatures of over 40C are forecast to swelter the northwestern provinces and the mountainous area in the central region. The number of hours in a day with temperatures above 35C is expected to be between 11-16 hours. The mercury is expected to drop to around 30C on Monday next week.