RUFOUS-WINGED SPARROW 



905 



of June, Tradition has the rains starting on San Juan's day, June 

 24, but they seldom do. Early July is a more usual time for rains to 

 start. These, in summer, tend to be very local — a downpour here 

 today, another there later, and mere drizzles elsewhere. Accurate 

 measurements of water available to plants in each area are obviously 

 impossible, and were not attempted. Even for the University of 

 Arizona campus, I cannot consider the figures given (see below) as 

 strictly accurate, but they show the trends of rainfall. 



RAINFALL 



JULY SEP NOV JAN MAR MAY JULY 



Rainfall at Tucson, Arizona (University of Arizona station) 



Fine dots= normal (median) 



Short dashes = calculated arithmetic mean, all years 



Solid line =1951-1952 



Longer dashes = 1957-1958 



The climatic picture of the fall, winter, and spring of 1951-52, 

 though quite similar to that of 1957-58, was strikingly different from 

 normal. The weather remained hot through Oct. 20, 1951, then 

 cooled off. Storms at the end of each fall month brought less rain 

 in September than later, but added up to a very wet fall in south- 

 western and central Arizona. It stayed cool and rainy through 

 Christmas, but 1952 opened with a long spell of warm, dry weather 

 from January 10 through February 29. This gave way abruptly to 

 a cold, rainy period from March 1 to 17; intermittent rains con- 

 tinued through at least April 28, though the weather warmed to 

 normal after March 25. 



Thus, since the start of weather recording at Tucson in 1868, only 

 two previous years (1905 and 1926) approached 1952 in the quantity 

 of rain that fell in March and April, and only 1870, 1924, and 1925 

 were drier in January and February. The total rainfall was normal 



