Chinanews, Beijing, June 8 - Though it is only the beginning of summer, Beijing, Tianjin, Hebei, Shanxi, Shandong, Henan and Shaanxi are struck by great heat waves. According to information by the National Meteorological Administration, the high temperature will last in the next three days.The highest temperature in Beijing on June 7 was 36 degrees centigrade, the highest in the last 30 years. Due to the high humidity, the incidence of sunstroke in the city might rise. The highest temperature in most part of north China will reach 35 to 37 degrees centigrade in the next two days, and even 39 degrees in some places.The weather on June 7 and June 8, the two days for National College Entrance Examination, will be relatively tolerable, thus it won't interfere with the examination. However, residents in north China still have to get ready to deal with the extraordinary heat wave these days.