The Harmattan is a dry and dusty trade wind.

It blows south from the Sahara into sub-Saharan Africa between the end of November and into March / April (winter). It "can" bring temperatures as low as 3 degrees Celsius, 38 F. (but not really often)
On its passage over the desert it picks up fine dust particles (between 0.5 and 10 micrometres).
In some countries in West Africa, the heavy amount of dust in the air can severely limit visibility and block the sun for several days, comparable to a heavy fog. The effect caused by the dust and sand stirred by these winds is known as the Harmattan haze, which costs airlines millions of dollars in cancelled and diverted flights each year, and risks public health by increasing meningitis cases. The interaction of the Harmattan with monsoon winds can cause tornadoes. Humidity drops to as low as 5 percent and can result in spontaneous nosebleeds for some. The wind has been blowing hard at times for the past couple days. The dust buildup inside the house can be amazing. In just a matter of hours I can write my name on the table again. Makes me feel like soft shoe dancing on the our concrete floors :-)

Side note: Judy found some imported Tortilla Chips, (only $2) really good ones, not date expired and actually fresh tasting. To celebrate she made some tomato salsa. Ahaaaa, so good! Its the simple things in life...