我国四季分明,季风性很强,冬半年多刮偏西风,夏半年多刮偏东风,特别在西北地区这一现象更为典型。舂、秋季是一年季节交替的关键时期,秋季又是北方地区收种的关键时节,因此掌握该时期的天气情况,对农事活动有着深刻的意义。然而,春、秋两季有着显然不同的气候特点,春季一般多刮大风,而降水量很少;秋季则是降雨最多的季节,相对刮大风的机会少。谚语“春风对秋雨”,这是不无道理的。有学者曾指出 China has four seasons and a strong monsoon climate. In the winter of the year, it is more prone to wipe its westerly winds. In the summer of half year, more winds are scraping eastward. This phenomenon is especially typical in the northwest region.舂 Autumn is the key period for the alternation of the year. Autumn is another key season for the harvesting in the north. Therefore, grasping the weather conditions during this period has profound meanings for the agricultural activities. However, the spring and autumn seasons have markedly different climatic characteristics. In spring, winds are generally more and more grizzly, while precipitation is less. In autumn, the season with the heaviest rainfall is the less chance of windy winds. Proverb “Spring on the autumn rain”, this is not without reason. Some scholars have pointed out