It's an annual, man made, weather phenomenon here in the Rio Grande Valley.
Farmers in Mexico are cranking up their agricultural, field clearing, fires down in the Yucatan Peninsula. The smoke rises high enough to get caught up in the prevailing winds which carry the pollutant all the way to the RGV.
The haze will peak Tuesday and Wednesday of next week.
Good news comes in the form of a cold front early Thursday. This next front promises to drop daytime highs into the low 80's and sweep out much of the smoky haze. There is a slight chance for showers and thunderstorms with the front but only a slight chance.