Maybe some bloom booster fertilizer would get things going for you. My bush beans are done, my roses were spectacular a month ago, 4:00s have just started, morning glories not yet.

I agree with Dorothy. The other possible issue is that the plants are getting too much nitrogen, which tends to push them to grow vegetatively and that can make them flower late.

My roses bloom on and off all summer and have done fine this year, my 4 o'clocks just started blooming within the last week, and my morning glories started blooming a couple of weeks ago, which likely is a little earlier than they bloom most years. Beans may not bloom once the temperatures are in the 90s, but if you can keep the plants healthy, the blooming will resume once the temperatures cool off again.

If you have had a lot of rain and cloudiness that might explain it, but not if other plants nearby that have received the same amount of rain are in bloom. And, I assume your plants get lots of sunlight. Plants grown in partial shade through heavy shade bloom later and in less quantity than plants that have plentiful sunlight, unless you have specifically choosen plants that do well in partial shade. (Four o'clocks are an example of a plant that blooms well even when grown in pretty shady locations).

My morning glories are nowhere close to flowering, except the yucky weedy white ones.

I have been on morning glory/weed vine patrol for weeks. They are growing like, uh, weeds. :) My roses are just starting their second flush. My four oclocks are not quite blooming, but I have to admit mine do not do well. I know they are supposed to grow abundantly, but mine never do.