Simoom (سموم samūm; from the root سم s-m-m, "to poison") is a strong, dry, dust-laden local wind that blows in the Sahara, Palestine, Jordan, Syria, and the deserts of Arabian Peninsula. Alternative spellings include samiel, sameyel, samoon, samun, simoun, and simoon. Its temperature may exceed 54°C and the humidity may fall below 10%.
The storm moves in cyclone (circular) form, carrying clouds of dust and sand, and produces on men and animals a suffocating effect. The name means "poison wind" and is given because the sudden onset of simoom may also cause heat stroke. This is attributed to the fact that the hot wind brings more heat to the body than can be disposed of by the evaporation of perspiration.
A 19th-century account of simoom in Egypt goes:
Egypt is also subject, particularly during the spring and summer, to the hot wind called the "samoom," which is still more oppressive than the khamáseen winds, but of much shorter duration, seldom lasting longer than a quarter of an hour or twenty minutes. It generally proceeds from the south-east or south-south-east, and carries with it clouds of dust and sand.
A Simoom also struck Santa Barbara, California in 1859 bringing the local morning temperature from a cool 77 degrees to 133 degrees within a couple hours. The temperature stayed in around 130 degrees for the majority of the day and left as quickly as it came leaving many animals dead and people fearing the end of the world had come. This temperature of 133 degrees held the record for a long time.