iy lire 
~% : 
300 B. N. A. BOUNDARY COMMISSION. 
the greater part of Montana, to the south, is estimated to be 48° * ; showing, 
if the observations are to be trusted, a lower mean temperature by two 
degrees on the forty-ninth parallel. Climatal lines, however, are not 
very strict or well marked on the western plains, and it is probable that 
the climate of a great part of the third steppe nearly coincides with that 
of northern Montana, where more continuous records exist than any 
available for the region to the north. 
708. The mean temperature for each month at Fort Shaw, one hun- 
dred miles south of the Line on the 112th meridian, is, in the following 
table, placed side by side with that of Winnipeg t :— 
Ft. Shaw. Winnipe Ft Shaw. Winnipeg. 
Saamaey o...Gver PEs, 21°28 SON! Hy aby 0 thes ahaha 70°22 65°87 
SeMReNRY Sid's te len fas 30°39 2°99.) August, 2y.s s\.saudvie<s bid 67°15 64°75 
SR: 8 in WN Gin 8p bet 36°58 9°00 || Séptember... si is 420555 54°04 51°29 
Ty a RN Cea es Pe 46°51 80-2154) Ogtoliers 2) svete cline 49°12 40°01 
MEME CUCU Fal tice a het ste Snes 56°04 51°18 || Nowenaber:-.4s s.saap exe 39°92 14°58 
The mean annual temperature of Fort Shaw is 47:33, while that of 
Winnipeg is 32:59. The temperature of the six warmer months, May to 
October inclusive, m northern Montana and the Red River country is 
pretty nearly equal, showing a balance of only about four degrées in 
favour of the former. The six winter months are, however, very much 
colder in the eastern locality ; and this notwithstanding the fact that Fort 
Shaw is about 3,000 feet higher than Winnipeg. Thus, while the mean 
annual temperature of the Red River Valley stands about 14 degrees 
lower than that of Montana, this is not brought about by any great 
deficiency of summer heat, but by the long continuance of steady cold 
weather in the winter. The extreme of winter cold is probably almost as 
great in Montana as in the Red River country, the thermometer at Deer 
Lodge showing a minimum of —30° F. in several years, but the, cold 
weather is not of long continuance. The snow fall is very light, and sel- 
dom exceeds a few inches in depth at any one time. The total annual 
precepitation—mean of two years—amounts to 8°95 inches only. 
As a pastoral and stock-raising country, the higher mean annual tem- 
perature gives the third plateau an important advantage over the region 
to the east. 

* U. 8. Geol. Surv. Territ., 1872, p. 811. 
tTemperature of Fort Shaw from the mean of two years. U.S. Geol. Surv. Territ,, 1871, p. 266, 
That of Winnipeg, from three years observations, is kindly supplied by Prof. Kingston. 

