Hello alkavijh! It does help to know what is your high temperature in your area. Though I imagine like in my old homeland, by that time we are entering the start of hot and humid summer that starts to peak by April. Pretty much most flowering plants likes lots of sun, good moist media, and you may have to do daily watering, since the heat and humidity can be intense, with application of fertilizer at the beginning.
I can suggest Jasmine sumbac, marigolds, some orchids like vandas, cattleyas and dendrobiums (but do provide some shade during the hottest time of the day), calamondin tree - it does have jasmine-like blooms then followed by the little tart fruits; tropical hibiscus. Oh, you can certainly try Adeniums and Plumerias too.
As to ongoing care for the plants, I would suggest too, that you try and search for various gardening blogs on the internet relative to your location. Our growing conditions here are rather different.
At the most, at times, when temperatures peak beyond 30C with the humidity factor added on top, most plants will just stop growing or doing any blooms till the conditions improve.
