Zinnias, marigolds, petunias, day lilys, iris, mums, snapdragons....
Etc etc.
Linda C

If you plant a shade plant and it gets full midday sun where you are, it will likely fry....but mid day sun for 2 to 3 hours should keep sun loving flowers blooming.
Is the spot shaded by trees or buildings? And is there any other thing about the spot that might keep sun loving flowers from doing their best? Like dry soil, gravelly conditions?
Linda C

I have the same type of sun in one of my borders and have found daylilies work really well there.

The problem with the zinnias is that they don't grow as big as the ones I have in all day sun. (I grow zinnias from seed). I am wondering how store bought already bloomed zinnias would do - probably okay.

Good luck

Carrie

Could you moderate the intensity at all? For example, a trellis, or pergola to give dappled light below and use the area perhaps for houseplants out for the summer.

Or use cachepot-type containers and plantings of, say, Echeveria varieties, Crassula, Aloe, large Sedums - with garden art, if that suits your style.

Some of the decorative grasses might also be useful, as foils for succulents or rugosa roses.

As Linda C asked, what is the source of the shade? If trees, know that they will be competing with whatever you plant not only for sunlight, but for water and nutrients as well. You may need to consider plants that will thrive in poor, dry soil, or adjust your watering and fertilization to compensate.

If it's a sandy or gravelly soil, it may not hold water and nutrients well enough for those flowering plants. If heavy with clay, it may drain too poorly.

Don't you love it ... you come here with a question and wind up with even more than you started out with. ;-)

Diane

There must be something else if marigolds are did not do something noticeable. Add calendula to you lists of to-try sometime.

But you do need to water a fair amount in intense mid day sun.
Linda C