248 



PROCEEDINGS OF THE NATIONAL MUSEUM 



woodlands to 21 iii ponderosa pine and 22 in Douglas fir zones. The 

 evaporative effect of winds, however, Unaits mesophytic vegetation 

 on exposed slopes so that correlations between precipitation and 

 elevation are often spurious for indexing vegetational distribution. 



80 r 



< 

 (r 



UJ 

 Q. 



:e 



UJ 



70 



60 



hi 

 o 



LlJ 



^ 50 



40 



30 



20 



> 8 



SAN FIDEL 6100 ft. 



EL MORRO 7218ft. 



nr. McGAFFY 8200 ft. 



1.0 L4 L8 2.2 2.6 



PRECIPITATION inches 



3.0 



Figure 2. — Cllmatograph of three weather stations in the Zuni region. (Plotted points 

 are mean monthly temperatures and precipitation; months are indicated by numbers. 

 Data compiled from U.S. Department of Commerce climatological summaries for New 

 Mexico, 1945-1957.) 



Air temperatures generally fall with increasing elevation, the annual 

 fluctuation being equally great at all stations (fig. 2). The number 

 of days between 32° F. extremes is 123-194 (x 162) below 7000 feet, 

 72-148 (120) above 7000 feet (U.S. Dept. Comm., 1945-1957). 

 Daily temperature variation is also considerable (table 1). Pearson 

 (1931, tables 3, 4) calculated June-September maximum and mini- 

 mum temperatures in New Mexico and Arizona as follows: 90, 55 

 (°F) in the grassland zone; 83, 52, pinyon-juniper woodland; 79, 46, 

 ponderosa pine zone; and 74, 40, in the Douglas fir zone. Hooper 



