>>13748183Sunny day works by clearing the skies of clouds and shit making it easy for the Sun or Moon to shine down. Rain, Hail, Sandstorms etc all would obscure the Moon and make it harder to Moonlight to reach the field.
Obviously Sunny Day in battle mechanics implies heat since the fire boost and water weakness and the name is obviously referring to the sun. But if you think about the fiction the move still works at night time and it's a weather move not a sun controlling power, that would be kind of extreme. So really Sunny Day must just clear the skies.
