Jan - Feb: cooler, fresher, dry.
March: dry, getting hotter.
April & May: dry, as hot as hell, no wind. Most expats try to hide in the home or office during these two months.
June - August: cooling down a little, a few heavy showers, usually in the late afternoon.
Sept - Nov: the height of the rainy season, don't be surprised if it rains all day, every day. And, I'm talking SERIOUS rain.
December: end of the rainy season, not to hot but plenty of sun for a great tan, the best month for me.
Enjoy and stay safe.
Happy Travelling!!