9 



Average annual and monthly precipitation at some Hawaiian ranches and other points — 



Continued. 



Statioc 



Eleva- 

 tion. 



Years 



of 

 record. 



July. 



Au a 



Sept. 



Oct. 



Nov. 



Dec. 



A nrmc»l 



A i 11.1 iucXl* 



Island of Hawan: 



feet. 





Inches. 



Inches. 



Inches. 



inches. 



Inches. 



Inches. 



Inch es. 





100 



2o 



10. 46 



12. 56 



10. 66 



10. 97 



13. 09 



11. 24 



136. 53 





2, 000 



6 



1. 41 



2. 38 



3. 55 



2. 04 



1. 28 



3. 95 



31. 11 





A AO£ 

 0, OoO 



c 

 O 



1 O./! 



i. y4 



O O™ 



O. /0 



1. 48 



1. 67 



O oe: 

 ZO 



5. 38 



23. 72 





9 i ^n. 

 Z, 10U 



9A 

 ^0 



9 no 

 Z. Uo 



o err 



o. oo 



6. 10 



4. 33 



A 01 



0. ol 



4. 77 



53. 28 



T7"^.V 1 rtlri TY1 ill 



97A 



It) 



4. 07 



4. Oo 



3. 78 



9 AT 



6. 07 



0. Uo 



5. 16 



55. 64 





Zk>\} 



1 A 



0. /I 



n i o 



4. 44 



5. 14 



8. 52 



8. 09 



87. 66 





ZO 



1 A 



10 



O r"7 



4. 13 



4. 02 



2. 24 



1. 47 



2. 75 



34.30 





600 



6 



6. 44 



5. 06 



4. 71 



3. 50 



4. 10 



9. 08 



66. 39 



Puuwaawaa ranch * . . _ . 



2, 736 



6 



3. 49 



1. 60 



3. 49 



1. 79 



1. 50 



2. 26 



29. 02 





4, 000 



i-6 



A AA 

 4 . O'J 



1 Oft 



/. oo 



4. 70 



O. 1 1 



8. 42 



6. 48 



78. 71 





Z, iZ[) 



Ol 



ZL 



Z. iSZ 



o. oo 



O 1 o 

 Z. LZ 



2. 67 



3. 17 



5. 13 



42. 40 



Island of Maui: 























z, 000 



OA 

 Z\J 



1.27- 



o net 



l. to 



2. 23 



2. ^4 



4. 82 



18 



47. 01 





4, 200 



oo 

 ZZ 



1. 69 



3. 50 



2. 90 



1. 95 



2. 46 



3. 36 



37. 90 





700 



11 



13. 18 



18. 33 



13. 39 



12. 31 



16. 93 



17. 38 



178.31 





1, 740 



14 



. 33 



. 86 



. 45 



1. 12 



2. 43 



S. 05 



22. 93 



Island of Oahu: 









j ■> - ! . 















3o0 



21 



4. 38 



5. 94 



6. 74 



6. 41 



8. 87 



9. 44 



83. 97 





100 



16 



2. 57 



4. 44 



3.90 



4. 30 



4. 96 



6. 80 



53. 97 



Tantalus 



1,360 



10 



6.54 



9.29 



9.56 



7. 17 



10.08 



11.51 



125.80 



Waianae 



6 



18 



. 33 



99 



. 97 



.98 



2. 65 



2. 83 



20. 77 



Waimanalo 



25 



18 



1.40 



1.76 



2.08 



2.50 



5.21 



6.97 



44.34 



Island of Kauai: 























342 



27 



4.76 



5.01 



4.47 



5.69 



6.95 



6.38 



69.28 



Kealia 



15 



12 



1.91 



1.99 



2.32 



3.76 



3.65 



4.44 



39.97 



Grove farm 



200 



27 



2. 21 



2.73 



2. 76 



3.62 



5.50 



4.86 



45.86 





900 



11 



4.94 



5.88 



5.16 



4.70 



5.97 



6.36 



70.31 



Kekaha 



40 



20 



.45 



1.14 



1.12 



1.20 



2.64 



2.76 



22.64 



Island of Molokai: 























800 



12 



1.18 



.99 



1.16 



1.63 



3.82 



5.27 



34.45 



Calculated from records, 1936-1911, inclusive. No record at Humuula in ly07. Average for Puakea 

 ranch high because of an exceptionally heavy rainfall in 1909. Normal should be about 50 inches annually. 



A study of rainfall statistics on the Hawaiian Islands reveals the 

 fact that the average annual rainfall at any point seldom falls much 

 below 20 inches. In the mainland States the line of 20 inches rain- 

 fall roughly follows the line of 100° west longitude and marks the line 

 between sure and uncertain crop regions. West of that meridian 

 much land is now taken up in "dry fanning" and the balance is in 

 ranch, mountain, or desert land. 



However, the fact that the greater part of the land in Hawaii re- 

 ceives over 20 inches of rain does not tell the complete story. Some 

 soils allow percolation so freely that most of the water passes beyond 

 the reach of plants ; some lands are so steep that nearly all is lost by 

 surface drainage; the precipitation is so heavy at times that no 

 opportunity for percolation is given, or it may be so light that all is 

 quickly lost by evaporation. Because of heat and wind, evaporation 

 is high at certain times and places and the drier the season and the 

 more the need for moisture, the higher is the rate of evaporation. Some 

 figures giving the effective annual and monthly rainfall would be of 

 more value in determining the crop possibilities of a given region. 



The nature of the vegetation determines the need for moisture. 

 With annual weeds and grasses a heavy rainfall for a short season is 

 best in order to start vegetation and push it to maturity. 



