Precipitation 



Over the 5 study years, precipitation for the months May-October varied from 7,18 

 to 12.24 inches (table 11). Usually over 50 percent of the total precipitation during 

 any growing season arrived in May and June, primarily the latter and sometimes as snow. 

 Precipitation diminished abruptly in July (fig. 10). Both July and early August were 

 relatively dry. After the middle of August, precipitation would usually increase again. 

 Snow was fairly common in the late August and September storms, but it would melt within 

 a few days. Precipitation ordinarily diminished again by late October. 



On an average, measurable precipitation occurred on 27 percent of the days from 

 May through October. Usually, June had by far the greatest number of rainy days, 

 although September occasionally had at least as many. Over the 5-year period, as many 

 as 20 precipitation days occurred in June and as few as two in July, two in August, and 

 one in September (table 11). The 20 days of precipitation in June, 1967 yielded 4.81 

 inches, a maximum monthly total for the 5-year period. 



No difference in amount of precipitation was observed between exposures , but some 

 difference was recorded between elevations. Stations at 8,200 feet received 0.11 inch 

 per week (a = 0.26) more precipitation than the stations at 7,100 feet, or 2.75 inches 

 more precipitation over a 6-raonth period. 



Table II .--Total monthly ipreoi-pitation (indhes) and rvmbev of preoipi- 

 taticn days per month over a 5-year period at the station on 

 the southwest exposure at the 7 ,100- foot elevation 



Year \ 



May \ 



June 



July ; 



Aug. . 



Sept . . 



Oct. 



Total 



1964 Precip. 





5. 85 



0.67 



0.89 



0.05 



0.70 



8.31 



Days 





16 



4 



4 



1 



3 





1965 Precip. 



2.96 



2.90 



1.59 



1.96 



2.16 



.67 



12.24 



Days 



9 



14 



8 



10 



15 



3 





1966 Precip. 



1.68 



2.45 



.39 



.55 



1.68 



.43 



7.18 



Days 



8 



12 



5 



3 



5 



4 





1967 Precip. 



1__ 



4.81 



2.05 



.18 



.67 



1.93 



11.81 



Days 





20 



9 



2 



4 



14 





1968 Precip. 



1.87 



4.14 



.15 



1.87 



2.23 



.92 



11.18 



Days 



12 



13 



2 



11 



12 



6 





5-year average: 

















Precip . 



2.17 



3.62 



.97 



1.09 



1.36 



.93 



10.14 



Days 



10 



15 



6 



6 



7 



6 



50 



Data not available for entire month; estimated as 2.17 for computation 

 of totals. 



19 



