The Harmattan is a dry and dusty West African trade wind. It blows south from the Sahara into the Gulf of Guinea between the end of November and the middle of March (winter). The temperatures can be as low as 3 degrees Celsius. 
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, and costs airlines millions of dollars in cancelled and diverted flights each year. The interaction of the Harmattan with monsoon winds can cause tornadoes. Humidity drops to as low as 15 percent and can result in spontaneous nosebleeds for some.
Nigerien folk wisdom claims that men and animals become increasingly irritable when this wind has been blowing persistently. However, the cool wind brings relief from the oppressive heat, which is why the Harmattan has earned the nickname "The Doctor".
- "Harmattan". Encyclopædia Britannica. Chicago: Encyclopædia Britannica, Inc. 2007.
- "Tuareg unrest". BBC, via Temoust. 2007-09-07. Archived from the original on 2007-12-30. Retrieved 2007-10-08.
- The Harmattan wind of the Guinea Coast, H. W. Braby, B.A., F.R.Met.Soc., Quarterly Journal of the Royal Meteorological Society, Volume 39 Issue 168, Pages 301 - 306, 1913
- Ikekeonwu, Clara (2007). The phonetics of Nigerian languages. Munich: Lincom Europa. p. 62.
- Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. Cite has empty unknown parameter:
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