LUCKNOW, May 11 -- Brace for rising day temperatures and heat wave from May 14 in East UP and from May 15 and 16 onwards in isolated areas of West UP, especially in southern parts. The day temperature is likely to gradually rise by 3 to 5degC during the next five days. Minimum temperature is unlikely to have any major change for the next 48 hours and will gradually increase by 2-4degC thereafter, the weatherman said. There are already trends showing day temperatures going up. Day and night temperatures in the state capital were 39.9 and 25.4 degrees Celsius on Saturday. The forecast for Lucknow is a partly cloudy sky becoming mainly clear. In all, at 15 Met stations across UP, day temperature was recorded in excess of 40 degrees. Varanasi BHU was the hottest in the state at 42.2 degrees C, Basti 42, Prayagraj 41.6, Kanpur IAF and Bahraich 41,2, Varanasi (airport) 41.1, Ballia 41, Sultanpur 40.9, Gorakhpur 40.8, Churk 40.6, Moradabad and Ghazipur 40.5, Fursatganj 40.4, Hamirpur 40.2, Ayodhya 40 degrees C. During the last 24 hours, very light to light rain was recorded at isolated places in both meteorological divisions of UP. The forecast for Uttar Pradesh is rain/thundershower very likely at isolated places over the state. The monsoon this year is likely to arrive in Kerala on May 27, roughly four days earlier. Clarity about the date of arrival/strength of monsoon in Uttar Pradesh will depend on its activity after it enters Kerala, said Atul Kumar Singh, senior scientist at Lucknow Meteorological office. Here are some dates of its arrival in different parts of UP: Gorakhpur on June 18, and Varanasi, Lucknow, Kanpur and Prayagraj on June 23....