This page is dedicated to discussion on the topic of the ‘windows of heaven’ — arrubot hashamaym and related expressions. I do have material on this topic that I have not published yet, in answer to commenter Mako. Until then Mako made some terrific points. I would note that it is important to not treat this expression in isolation from some other related expressions (like ‘treasuries’ or ‘storehouses’ of heaven). Cheers!
The Cosmos of the Hebrew Bible
Exploring the true cosmology of the Hebrew Bible in light of the solid dome sky (‘firmament’) and flat earth claims