占四時甲子雨
This is a poem from the Complete Tang Poems about weather prediction. The Jiazi day refers to the Wood Rat day, the first day in the 'sexagenary cycle', a 60-day cycle used in the chinese calendar. https://zh.wikisource.org/wiki/全唐詩/卷880#占四時甲子雨
占四時甲子雨
JUDGMENTS ON RAIN ON THE JIAZI DAY IN THE FOUR SEASONS
春甲子雨，赤地千里
If it rains on a Jiazi day in Spring; scarlet land for a thousand miles (i.e. drought)
夏甲子雨，撑船入市；
If it rains on a Jiazi day in summer, boats will be rowed into market.
秋甲子雨，禾頭生耳；
If it rains on a Jiazi day in autumn, ears will grow on the rice-tops
冬甲子雨，牛羊凍死
If it rains on a Jiazi day in winter, cows and goats will freeze to death
鵲巢下地，其年大水。
When Magpies nest on the ground 下地, big flooding that year