Insects are not flying about in strong winds, cold temperatures and in persistent rain. When adverse weather conditions exist for more than a day or two, offering food is imperative. Without intervention, in the form of supplemental feedings, the purple martins will starve to death.

Supplemental feeding adult purple martins will increase survival rates when extended rain, cold or wind makes it difficult or impossible for adults to catch insects. Teaching your purple martins to accept feedings is a rewarding experience that is a lot easier than one might think.

Hunger and the insects motion, as it is flung into the air, is a strong stimuli and most report that within 15 minutes the martins are eagerly accepting both meal worms and crickets. After being taught to accept these feedings many landlords prepare scrambled eggs which makes a very cost effective and convenient alternative to insects.

Eventually, once the martins learn to accept this non conventional food source, they will even accept feedings of elevated platform feeders.
The PMCA (Purple Martin Conservation Association) has some information to help your purple martin colony survive these extended periods of poor weather conditions.