CLIMATE.

The Climate of Washington Territory.Climate is a matter of temperature, moisture and atmospheric dynamics. The general law of temperature is that the farther north the colder the weather; and yet currents of water and prevailing winds may give to the country a climate geographically belonging to quite a different latitude. We know how this is with England, which, judged by latitude, ought to be colder than Maine, but which, in fact, has one of the mildest and most equable climates in the world. England is farther north than Washington Territory, which latter is in the latitude of France; but it is also in the latitude of Montana, Dakota and Maine, States remarkable for sudden changes and for terrible cold. But it is well known that our Pacific States, at least on their western borders, have a temperature free from extremes in both summer and winter. Taking July and January as the hottest and coldest months, it will be found that the average temperature at San Francisco and Puget Sound is from 7° to 14° cooler than it is in the Rocky Mountains and in New England during the same months. And on the other hand, taking January as the coldest month, we find that Bismarck, Denver, New England, etc., are 30° to 40° colder than the points on the Pacific. In other words, that the range of the thermometer between extremes averages near 50° more in the East than it does in the West in the localities named; a very great difference when we consider comfort, health, cost of living, and opportunity to labor in the open air.

Mild and equable.This greater mildness and equability of temperature on the Pacific Coast is to be ascribed to the winds and currents of the great ocean. During the summer the winds come from the northwest, and during the winter from the southwest and south. Much influence in tempering the cold of winter is ascribed also to the Japan Current, mentioned under a former head. It does for the Pacific Coast what the Gulf Stream does for England.

The same causes regulate also the rainfall on the Pacific Coast. In one respect there is the same peculiarity along the whole coast, namely, dry summers and, comparatively, wet winters. There is, however, a gradual increase in the amount of rainfall northward from San Diego to Sitka; so that when we reach Washington Territory we do not find the excessive dryness which characterizes the summer climate of California.

The figures of different authorities do not agree exactly as toRainfall. the precipitation on the Pacific Coast: for example, in the older volume on Rain Tables, published by the Smithsonian Institution, the annual rainfall and melted snow on Puget Sound, measured at Steilacoom, near Olympia, from 1849 to 1867, amounted to 43.98 inches. Governor Semple, however, gives from Sergeant McGovern, in charge of the station, a total of 53.89 inches annually, measured at Olympia from 1878 to 1886. But I find in the report of the chief signal officer to the War Department for 1884, that the average from July 1, 1877, to December, 1883, for Olympia, was 62.81 inches. This difference of nine inches is partly accounted for by the fact that the precipitation in the subsequent years not included in the report of the Signal Service Bureau, namely, 1884, 1885 and 1886, averaged only 41.88 inches, which would, in great measure, relieve the discrepancy. It will probably turn out on further observation that 53 inches is about the total annual rainfall for Puget Sound. But according to the report of the chief signal officer for 1884, we have the following annual totals: San Diego, 9.40; San Francisco, 23.32; Portland, Oregon, 54.16; Puget Sound, 62.81; Sitka, Alaska, 97.28 inches.

Comparing these with points farther east, we have Bismarck, Dakota, 21.35; Denver, 14.97; Sandusky, Ohio, 41.43; New Haven, Connecticut, 51.55; Norfolk, Virginia, 52.14 inches.

The value of rainfall depends more on its distribution among the months than on its annual aggregate. England has but 25 inches rain per annum, but it comes at such times as makes it most effective. The rains on the Pacific Coast are not distributed in the most favorable way for agriculture—the summers being too dry. At San Diego there is less than one-third of an inch in the three summer months, and still less at San Francisco. On Puget Sound, for that time, the fall is 2.57. In Washington Territory the spring rains are as abundant as in the Atlantic States, and the summer breezes seem laden with moisture.

No blizzards or cyclones.In respect to cold waves, winds and storms, Washington Territory is singularly favored. There is nothing to correspond with the blizzards, northers, hurricanes and cyclones which trouble some other States. Even ordinary thunder-storms are rare. The climate of East WashingtonDifferences between East and West Washington. is different from that of West Washington, and yet, when compared with that of Montana and Dakota, it will be seen that it is really transitional and intermediate between the climates on each side. The range of thermometer from the heat of July to the cold of January is, at Bismarck, 65°; at Spokane Falls, 45°, and on Puget Sound, 22°. And, in like manner, the amount of rain is intermediate between the heavy rainfall of the Sound and the lighter rains of the Rocky Mountain country. The explanation of this is, that while the Cascade Range, like all high mountains, condenses the moisture of the air on the windward side and changes its temperature, yet this range is not sufficiently high and cold to have the effect of the Himalayas or the Andes in depriving the leeward lands of rain.

The mountain rim of the plateau country has not the moisture which distinguishes the west side of the Cascade, and it varies in its amount at different places.

Some statements have already been made in reference to the dryness and summer heat of the Yakima Valley on the east flank of the main mountain. The mountains running along the Canada line have probably a better summer climate than the east side of the main mountain. I do not know how it is with the Cœur d'Alene and Blue Mountains, but the climate of the plateau has no unusual character in the matter of temperature. Half of the States of the Union have as great or greater extremes; but the plateau has less than half the precipitation of Puget Sound, as shown in the tables given on pages 56 and 57. And the rainfall in the summer is so scant that one would not, a priori, expect any form of vegetation to progress at all. These meteorological phenomena render almost unaccountable the facts of agriculture, which will be given hereafter.

Chinook wind.The Chinook wind, which springs up in winter and melts the snow on the plateau, and to some extent in the mountains, is simply a southerly wind, such as is common in the Mississippi Valley and even on the Atlantic seaboard. In the Pacific States it does not, from the descriptions, appear to differ from the breezes of the coast, except in its greater strength and steadiness. I heard an intelligent gentleman, residing in Spokane Falls, say that he thought the Chinook was a disadvantage in winter, as it caused a disagreeable thaw, and so relaxed the human system as to render it more sensitive to cold; but generally the Chinook is enjoyed in East Washington.