Are birds impacted by severe storms? Absolutely! There's a great article in the KOS Bulletin by Max Thompson about a Red-bellied Woodpecker death: https://www.ksbirds.org/kos/bulletin/Vol45No2.pdf
Dan's question is one that I seem to field every summer. So many things can impact breeding birds in one's own neighborhood. In the case of hummingbirds there is a fair amount of nesting site fidelity as well as wintering site fidelity. So if some tragedy struck in a wintering area it may have wiped out all the individuals that had been nesting in your yard/neighborhood.
I saw a noticeable drop in hummer activity from Memorial Day to the first week in June indicating that the last of the migrants had likely moved on. Additionally, since June 1st I've noticed a big drop in morning bird song. It's warmer PLUS everything is into serious nesting mode. While I did detect a drop in the number of hummers, we still have a LOT of them here at the farm. So Dan, all of yours may be over here!
Kidding aside. Keep the feeders up and change nectar regularly. If you see zero activity for ten days then there are likely no nesting hummers in your area and you can probably take down your feeders, or reduce the number, until southbound migration kicks in the second half of July.
