Table 1. — 



Variation in summer precipitation 



Weather 

 station 



Month 



May 



June 



July 



Normal Max. Min. 



Anchorage 0.51 2.00 0.02 



(Cook Inlet) 



Bethel .89 2.50 .02 



(West Central) 



Fairbanks .74 1.75 .07 



(Interior Basin) 



McGrath .94 1.98 .34 



(Interior Basin) 



Normal Max. Min. Normal Max. Min. 



0.89 2.94 0.03 1.55 3.25 0.19 



1.20 2.48 .30 2.29 3.95 .49 



1.37 3.52 .21 1.92 4.24 .40 



2.06 4.36 .42 2.32 4.73 .76 



Growing conditions early in the season de- 

 pend upon fall and winter moisture because too 

 little precipitation falls early enough in the spring 

 to promote plant growth. A deficiency of winter 

 precipitation or early loss of snowpack may indi- 

 cate the possibility of early periods of high 

 flammability; in addition, this set of circum- 

 stances can cause deeper than normal drying 

 of ground fuels which so often means a greater 

 than usual resistance to control of fires. For 

 most reporting stations, the monthly precipita- 

 tion increases during the summer. Less than 20 

 percent of the normal annual precipitation falls 

 between April and June. Only a few interior 

 stations report more than 35 percent of their 



annual precipitation during the period generally 

 considered the growing season. 



The amount of moisture that falls in any 

 single storm period is important to fire control. 

 The frequency of moisture occurrence affects the 

 flammability of the vegetative materials and the 

 rate of buildup of fire season severity. Rainfall 

 intensities greater than 0.25 inch in any one day 

 occur but seldom (table 3). Virtually no precipi- 

 tation falls on three-fourths of the days in May. 

 At very few stations did more than 0.26 inch of 

 precipitation occur on one or more days during 

 May. During April, the weather is even drier. 

 In May and June both frequency and intensity 

 of rainfall gradually increase. 



Table 2. — Percent of normal annual precipitation, April through July 



(Av. 1950-58) 



Weather 





Month 





Seasonal 

 percent 

 of annual 



Annual 

 ppt. 



station 



April 



May 



June 



July 















Inches 



Anchorage 



2.8 



3.6 



6.2 



10.9 



23.5 



14.27 



Bethel 



3.0 



4.9 



6.5 



12.6 



27.0 



18.17 



Fairbanks 



2.4 



6.2 



1 1.5 



16.1 



36.2 



1 1.92 



Fort Yukon 



2.6 



4.9 



10.9 



14.8 



33.2 



6.52 



Galena 



1.3 



4.3 



1 1.6 



18.6 



35.8 



14.55 



McGrath 



2.6 



4.9 



10.8 



12.1 



30.4 



19.13 



Northway 



3.1 



6.3 



17.6 



25.6 



52.6 



1 1.34 



26 



