最高最低气温出现时间分析

对新乡气象站2012-2013年每目的最高最低气温出现时间进行分析发现，在正常出现时间之外，有许多异常情况。剔除异常时间点，对正常时间进行统计得到：日最高气温冬半年平均出现在14～15时，夏半年在15～16时；最低气温冬季在07时左右，夏季在05：30前后。两年中有22％的温度极值在异常时间点出现。异常极值的出现主要由冷锋、强冷空气、云、降水、风、雾、霾等因素引起。当气温日较差比较小时，气温极值出现的时间和地点存在随机性。

Analysis of Occurrence Time of Maximum and Minimum Temperature

By analyzing the occurrence time of daily maximum and minimum temperature of Xinx- iang station from 2012 to 2013, many exceptions were found. When abnormal points were eliminated, the results show that the daily maximum temperature mostly appeared between 14：00 and 15：00 in winter, while appeared between 15：00 and 16：00 in summer and the minimum temperature mostly appeared at a- round 07：00 in winter, while 05：30 in summer. Mainly caused by factors such as cold front, strong cold air, clouds, precipitation, wind, fog and haze, the occurrence time of 22 percent of temperature ex- tremes in the two years doesn＇t comply with the rules mentioned above. There is randomness in the oc- currence time and space of temperature extremes when diurnal temperature range is small.