Apr. 1, 1925 
Relation of Weather to White Pine Blister Rust 
603 
PRECIPITATION IN THE NORTH¬ 
WEST 
Infection of Ribes and probably 
nearly all infection of pines is dependent 
upon moisture conditions during the 
summer months. This statement is 
based largely upon the writer’s obser¬ 
vations and experiments upon the 
rust in the Eastern States. In some 
localities near the coast fog may be an 
important factor. Precipitation rec¬ 
ords, however, have been found to 
indicate very well the moisture condi¬ 
tions in any given locality, that is, 
with a few exceptions, the total 
precipitation for a month indicates 
fairly well the favorableness of the 
weather during that month for the 
development of the rust. 
Precipitation records (Table XII) 
for Vancouver are representative of the 
moisture conditions for practically all 
the coast region in which the rust 
has been found. They also illustrate 
very well the variation in amount 
which may be expected in different 
years at any place in the white pine 
country (Tables XIII to XVI). 
Table XII.— Precipitation, in inches, 
of rainfall for June, July, and August 
at Vancouver, B. C. 
Year 
June 
July 
August 
Total 
1913_ 
3. 75 
2. 02 
0. 85 
6.62 
1914_ 
3.58 
.42 
.75 
4. 75 
1915_ 
.91 
.91 
.36 
2.18 
1916.. 
1.34 
5. 35 
.58 
7. 27 
1917_ 
5. 40 
.48 
.93 
6. 81 
1918... 
1.00 
2. 20 
4. 50 
7. 70 
1919... 
.98 
. 15 
1.15 
2.28 
1920_ 
3.08 
.67 
2. 91 
6. 66 
1921 . 
3. 64 
.32 
.84 
6. 80 
1922_ 
. 17 
.02 
2. 01 
2. 20 
1923. 
2. 08 
.52 
1 
Table XIII.— Average summer precipi¬ 
tation, in inches, for stations at or 
near which infection has been found 
upon pines 
June 
July 
Au¬ 
gust 
Total 
or aver¬ 
age for 
season 
Agassiz, B. C_ 
4. 54 
2. 05 
2. 55 
9.14 
Blaine, Wash_ 
2.12 
.88 
1. 22 
4. 22 
Enderby, B. C_ 
2. 06 
1.29 
1.21 
4. 56 
Ferguson, B. C_ 
2. 64 
2. 01 
2.06 
6.71 
Pemberton, B. C_ 
1.46 
.97 
1.51 
3.94 
Revelstoke, B. 0_ 
2. 69 
2. 49 
2. 49 
7.67 
Vancouver, B. C... _ 
2. 59 
1. 31 
1.74 
5. 64 
Table XIV.— Average summer precipi¬ 
tation, in inches , at stations in the in- 
. land region of white pine 
June 
July 
Au¬ 
gust 
Total 
or aver¬ 
age for 
season 
Cranbrook, B. C_ 
1.62 
1.51 
0.93 
4.06 
Enderby, B. C_ 
2.06 
1.29 
1.21 
4. 56 
Ferguson, B. C_ 
2. 64 
2.01 
2.06 
6. 71 
Nelson, B. C_ 
2. 44 
1. 70 
1.51 
5. 65 
Revelstoke, B. C_ 
2. 69 
2. 49 
2. 49 
7. 67 
Rossland, B. C_ 
2. 33 
1.38 
1.23 
4.94 
Priest River, Idaho.. 
1.73 
1.13 
1. 17 
4.03 
Kellogg, Idaho_ 
1.99 
1.10 
1.07 
4.16 
Wallace, Idaho__ 
2.15 
1.13 
1.21 
4.49 
Davson, Mont_ 
2. 35 
1.25 
1.22 
4. 82 
Fortine, Mont... ... 
2.71 
1.52 
1.48 
5.71 
Heron, Mont. _ 
1.89 
1.46 
1.22 
4. 57 
Poison, Mont_ 
2. 22 
1.17 
.93 
4.32 
Table XV.— Average summer precipi¬ 
tation, in inches, at stations in Western 
Washington, Oregon, and Northern 
California 
June 
July 
Au¬ 
gust 
Total 
or aver¬ 
age for 
season 
Aberdeen, Wash. ... 
3.36 
1.17 
1.06 
5.59 
Cedar Lake, Wash... 
5.23 
2. 34 
2. 48 
10.05 
Glenoma, Wash_ 
2. 43 
1.17 
1. 50 
5.10 
La Center, Wash_ 
2.36 
.95 
1.06 
4.37 
Quinault, Wash_ 
5.29 
1. 53 
2.17 
8.99 
Sedro Woolley, Wash. 
2. 68 
1. 46 
1. 70 
5.84 
Cascade Locks, Oreg. 
2. 39 
.80 
.92 
4.11 
Cascadia, Oreg_ 
Government Camp, 
3.16 
1.04 
1.05 
5. 25 
Oreg. - 
3. 28 
1. 58 
1.90 
6. 76 
Prospect, Oreg . J ... 
1. 44 
.66 
.32 
2. 42 
Grants Pass, Oreg_ 
.85 
. 17 
.23 
1. 25 
Jacksonville, Oreg_ 
.96 
.33 
.32 
1.61 
Medford, Oreg _ 
.84 
.43 
. 13 
1.40 
Montague, Calif_ 
.75 
.45 
.20 
1.40 
Sisson, Calif_ 
.62 
. 16 
.30 
1.08 
Summit, Calif.. _ 
.56 
.22 
. 11 
.89 
All available data show somewhat 
less summer precipitation in the “In¬ 
land Empire” and in the greater part 
of western Washington than in the 
coast region of British Columbia. The 
amount of precipitation for the sum¬ 
mer months diminishes southward. 
In southern Oregon and northern Cali¬ 
fornia many seasons have no precipita¬ 
tion during the summer season. Table 
XVI, precipitation for Summit, Calif., 
represents the conditions at nearly all 
places in the sugar-pine country. This 
shows that rarely is there a summer 
with precipitation equal to that of the 
driest of the British Columbia stations 
at which the rust has been found. 
It is to be noted that, as a rule, the 
summers with the greatest amount of 
northerly wind have the least precipita¬ 
tion. 
