“Conventional wisdom tells us that birds migrate north in spring and south in autumn. Some species also migrate in summer, though these movements are more modest and regional, rather than long-haul, intercontinental voyages. And they often head in counterintuitive directions as birds seek out specific seasonal resources instead of making a beeline for their winter range.” – All About Birds, 2014
The article was written in seven years ago, so certain flight patterns might have shifted. Other resources are included.