The Nogales Climate during the year

Precipitation

In our region there are two rainy seasons along the year: during the Summer and Winter. Different processes originate them.

Summer rains are generally intense, although covering small areas, while those of Winter cover great land extensions (sometimes the whole of Northwest Mexico), although they are not strong.

The average precipitation in the Municipality is, according to INEGI, 488.3 mm (1986 to 1995), while according to the United States NOAA, in Nogales, Arizona, the precipitation is 473.2 (1892 to today).

Within the Municipality there have been floods in 1905, the Summers of 1909 and 1914: during the Winter of 1914, from September 27 to 29 of 1926. Also, the great flood of August 7, 1930, which demolished many houses in Both Nogales, with five lives lost as well as causing a great amount of damage. There was another Summer storm on July 5, 1957, which caused three deaths and left without home some 60 families, and whose legacy was the building of the dam at Colonia La Granja.

Besides this, there was another Winter flood between December 22, 1965 and January 2, 1966. Another one on October 1977 and one more ending August and beginning September of 1980, which caused enormous damage in all the region located betweeen Imuris and Tucson: It demolished the bridge over the Santa Cruz River in Tucson. Finally, the great flood between October 1 and 3, 1983, related with Hurricane Octavio, when there were 203 mm of precipitation in a single day in Nogales (almost half of the yearly precipitation average), which also caused enormous damage in Northern Sonora and Southern Arizona. In Magdalena, the bridge situated in the Southern edge of town was demolished. We can see at the left a photo of this flood, in Tucson.

Besides this, in a year when we have precipitation under 70% of the average, is considered a year of drought. However, this is not a criteria that covers the whole scene, as in a year the rainy season can be delayed -even though there is enough precipitation-, and therefore the vegetation cannot use that water. Besides this, the situation is aggravated when there are a continuous number of years with drought, and their consequences are accumulated.

Droughts

In our region, we have had extended droughts between 1981 and 1893, 1898 and 1904, 1921 and 1923, 1932 and 1936. The great drought between 1942 and 1964, as well as the one between 1973 to 1977. We can see the effects of the drought on the cattle in the photo at the right, which was taken in 1903.

All of this is a manifestation that the region around Nogales suffers of great variability in it's rain amounts, as there have been years with floods immediately being followed by droughts extending for several years.

Winds and Snow

Now, regarding other climatic factors, the winds in the Municipality prevail from the South during the Summer, and North during the Winter. The maximum speed registered during some gusts has been of 110 Km/h (68 Mph) during some Summer storms.

During the Winter, there are an average of three snow precipitations. Historically, the deepest snowfalls have occurred on March 12, 1922, and December 4, 1971, both with a depth of 6 inches.

The average yearly temperature, according to INEGI, in the Municipality of Nogales is of 17.8 Degrees Centigrade, and it can vary along the year between a Maximum/Minimum of: in January of 18°/-3°, and

July of 34°/18°, although there have been registered maximum extreme temperatures of 44.5° C on June 26, 1990, and a Minimum of -20° C on December 8, 1978. A graph showing the extreme temperatures can be seen at the left.