You might be experiencing abnormally warm winters that cause early blooming flowers that are quickly zapped by a harsh early spring cold front. These seasonal mismatches cause bees to emerge early only to find their sources of nectar frozen and withered.
Heat and drought can affect flowering plants as well. Scarce nutrition is a problem for our symbiotic bee neighbors who already face threats from parasites and pesticides.
Here is a world map from the Denver Post of drought-tolerant flowering plants.
Check this resource from Oregon State University for a variety of cold-resistant North American plants.
North Carolina State University provides a list of drought-resistant North American plants.
And here is an article on cold-resistant flowering plants native to Asia.
Please share these links and start a conversation. Nothing changes unless we begin.