By contrast the choleric humour was seen to be weakest at the winter solstice, corresponding to the coldness and moisture of the winter. Subsequently the melancholic humour was seen to be most powerful at the autumnal equinox, corresponding to the coldness and dryness of the autumn. By contrast the melancholic humour was seen to be weakest at the vernal equinox, corresponding to the heat and moisture of the spring. Finally the phlegmatic humour was seen to be most powerful at the winter solstice, corresponding to the coldness and moisture of the winter. By contrast the phlegmatic humour was seen to be weakest at the summer solstice corresponding to the heat and dryness of the summer.
All time is measured out by motion, and that the original of all motion is the heavens.
From which conversion of times and years, all changes proceed, both heat and cold, dryness and moisture, by which four is caused life and death, generation and putrefaction, increase and decrease of elementary things. A Beginner's Guide by Dylan Warren-Davis.