Calm weather in June sets corn in tune.

The proverb presents calm June weather as favorable to a growing corn crop. “In tune” suggests that the crop is developing as it should.

More broadly, it expresses the hope that suitable weather at an important stage of growth will help a crop prosper, without promising a particular harvest.

Use it when discussing June weather and its possible effect on crops, especially to express approval of settled conditions. It works as a hopeful observation rather than a firm prediction.