I suspect that you've been bollocking the lacquer on very wet, because of the heat, and trying to get a decent flowing finish... this is a problem with cheap acrylic lacquer, it tends to go cloudy when built up too quickly...
You may also be seeing a problem called "Floatation" this forms in the basecoat, and on lighter colours is usually invisible to the untrained eye, but is magnified when given a few coats of lacquer...
In my experience, today was just too warm to paint, especially with acrylic aerosols, wait for a temp drop to 15 to 22, and build up in lighter coats...
Thom