On Rohiṇī-yoga - Verse 35

If, towards nightfall, on the Rohiṇī Yoga day, when cattle, led out in the morning, re-enter the town, the first animal so entering should be either an ox or a goat of white colour, there will be no rain; if it should be an animal black-white in colour there will be moderate rain; if in the last case the black colour should predominate, the rainfall will be abundant. If the animal that enters first should be of any other colour, there will be slight rain.