LUCKNOW, June 27 -- Lucknow sweated through a blistering maximum temperature of 42.4degC, a staggering 6.3 degrees above normal, becoming the fifth-hottest city in the country on Friday. Residents found little relief even after sundown, with minimum nighttime temperatures hovering above the 30degC mark. Out of the 11 hottest cities in India with temperatures of 42 degrees and above, nine were from UP. Rohtak in Haryana was the hottest at 43.4 degrees. UP's Lakhimpur Kheri (43.2) was the second hottest city, followed by Banda and Agra (43), Kanpur, Fatehgarh and Aligarh (42.2). Barabanki and Prayagraj (42) were the last two cities on the list. Lucknow recorded a minimum temperature of 30.4 degrees, which was four notches above normal.It is likely to experience heatwave conditions during the day on Saturday, with maximum and minimum temperatures hovering around 42 and 31degrees, respectively. Due to limited weather activity across the state on Friday, heatwave conditions prevailed in Shahjahanpur, Ghazipur (41), Ballia (41.3), Sultanpur, Varanasi BHU and Bareilly (41.5) while Bahraich (41.8) experienced severe heatwave conditions. In the absence of significant weather activity, this spell of heatwave conditions is likely to continue across the state until June 28. Subsequently, with a spell of rainfall likely to commence on June 29 and intensifying to widespread rain by June 30, conditions are favourable for the Southwest Monsoon to enter UP within the next 3 to 4 days and advance rapidly thereafter. Thunderstorm/lightning accompanied with gusty winds (speed 40-50 kmph) is very likely at isolated places over east UP. Regional Meteorological Centre, Lucknow, issued a yellow alert for heatwave, thunderstorms, lightning with probability of gusty winds for weekend (Saturday and Sunday). The Met department predicted high probability of heatwave conditions in 26 districts, including Lucknow, Barabanki, Kanpur Dehat, Kanpur City, Unnao, Sitapur, Hardoi, Gonda, Lakhimpur Kheri, Shamli, Bareilly, Pilibhit, Sambhal and surrounding areas.There is also a forecast for probability of thunderstorms, lightning and gusty winds (40-50 km/h) in over 25 districts including Banda, Chitrakoot, Prayagraj, Pratapgarh, Sonbhadra, Mirzapur, Chandauli, Varanasi, Sant Ravidas Nagar, Jaunpur, Ghazipur, Azamgarh, Mau, Ballia, Gorakhpur, Sant Kabir Nagar, Basti, Kushinagar, Maharajganj, Siddharthnagar, Raebareli, Amethi, Sultanpur, Ayodhya, Ambedkar Nagar, and surrounding areas. For Sunday too, there is a yellow alert for high probability of heatwave conditions, thunderstorms, lightning, high probability of gusty winds (40-50 km/h) in the many parts of UP....