summer or winter rainfall season

Spring or autumn rainfall seasonality is an index derived from two ratios. The ratio of spring (Sep-Oct-Nov) to autumn (Mar-Apr-May) rainfall totals (minus 1) are assigned positive values when rainfall in spring is greater than rainfall in autumn. The ratio of autumn to spring rainfall totals (plus 1) are assigned negative values when rainfall in the autumn is greater than rainfall in spring.春、秋季降水季节性是一项由两个比率推导得出的指数。春季（9月—10月—11月）降水总量与秋季（3月—4月—5月）降水总量的比值（减1）在春季降水量多于秋季时被赋予正值。当秋季降水量多于春季时，秋季与春季降水总量的比值（加1）会被赋予负值。