390 METEOROLOGY OF THE CASCADES. 
Pacific Railroad Exploring Expedition; and also, herewith, the observations tabulated according 
to the form established by the Smithsonian Institution. 
The meteorological observations commenced July 2d, and continued, with an interruption of 
a few days only, from July 17th to July 21st, until November, embracing a period of nearly five 
months, and the entire country from Fort Vancouver, Washington Territory, to Fort Colville, 
Washington Territory, north of the Columbia, and the return through the same distance south of 
the Columbia, including the country east and west of the Cascade range, and at one point 
approaching within two hundred miles of the Rocky mountains. At only two points were the 
observations continued for a sufficient time to form a correct estimate of the climate at the season 
of the year in which they were taken—at the camp on the Wenass river, and in the valley of 
the Yakima. 
The thermometer for the month of July indicates a temperature ranging— 
From 44° to 66° at sunrise. 
From 65 to 74 at9 a. m. 
From 78 to 94 at3 p.m. 
From 69 to 83 at 9 p. m. 
Weather clear and pleasant; general direction of wind northwest; no rain. 
For the month of August— 
From 48° to 64° at sunrise. 
From 58 to 76 at9 a.m. 
From 71 to 88 at 3 p.m. 
From 52 to 79 at9 p.m. 
Weather generally fair; general direction of wind south and southwest; rain on 7th, Sth, and 
9th instant. 
For the month of September— 
From 42° to 58° at sunrise. 
From 51 to 73 at9 a.m. 
From 58 to 84 at3 p. m. 
From 50 to 73 at9 p.m. 
Weather unsettled; wind, general direction south and west; rain fell on 1st, 2d, 13th, 15th, 
16th, 23d and 24th instant. 
For the month of October— 
From 10° to 59° at sunrise. 
From 47 to 67 at 9 a.m. 
From 51 to 83 at3 p.m. 
From 41 to 70 at9 p.m. 
Weather cloudy; wind south and southwest; rain fell on the 14th, 15th, 16th, 17th, and 30th 
instant; snow fell on the night of the 23d and morning of 24th, 
It will be observed, from the statement and from the tables, that the disproportion between the 
temperature at sunrise and mid-day is very great—a peculiarity of the climate noted in Green- 
how’s History of the Northwest Coast, and I believe by other authorities. The rise in the ther- 
mometer from sunrise to 11 o’clock was in many instances noted to be as high as 15°, and 
during the hottest days experienced late in August, at sunrise the thermometer stood as low as 40°. 
I have no recollection of a single day on which a fire was uncomfortable during the time just, 
preceding and succeeding sunrise. 
The heat was not generally oppressive, except in the sun, throughout the march. Rain fell on 
the occasions noted above. 
At Chequoss, on the summit of the Cascade range, August 9th, there was a severe storm, 
lasting but a few moments, however, of mingled hail and rain, accompanied by a strong gale 
from the southwest. 
