Seoul, June 9 : South Korea experienced the warmest-ever spring this year, with the average temperature spiking to the highest level since 1973 due to warm winds from inland China and a heat wave from Southeast Asia, the weather agency said on Friday. The average temperature across the country during the March-May period stood at 13.5 degrees Celsius, 1.6 degrees higher than the average spring season temperature and the highest point since 1973, when the country's weather observation networks were laid out nationwide, Yonhap News Agency quoted the Korea Meteorological Administration as saying. Last year, South Korea also saw its average spring season temperature hit the then record high of 13.2 degrees, a level previously recorded once in 1998. The weather agency attributed the unusually hot spring to warm northward winds fanned by high atmospheric pressure east of South Korea and warm air blown from China's inland. In April, in particular, the "monster" heat wave that engulfed Southeast Asia also drove up the temperature in South Korea, the weather agency said. /IANS