Today was supposed to be sunny and warm; but it wasn't.
To prevent any such lapse tomorrow I will invoke the Ladybird, with those words:
Marienkäfer, fliag noch Mariabrunn, und bring uns heit und moagn a recht a schene Sun!
This has to be said just when the ladybird takes flight, as is the case here. And it ensures that sunny weather is to follow.
This never ever fails, says folk belief.
Well, I hope so. If not then I'll have to file a complaint with our weathermen.