16 
soil are not frozen. The vegetation in Wood Buffalo park usually has its 
spring aspect well developed during the first week of June. Birches and 
poplars are yet in a small-leafed state on June 1, whereas Pulsatilla 
ludoviciana is rather past the height of its flowering and Calypso borealis 
is in its best development. In the spring of 1928, the writer found the Pine 
Lake region to be several days later in the development of its spring flora 
than the districts nearer the river. The autumn is usually reckoned as 
beginning about the middle of August. The writer experienced freezing 
temperatures on the Salt Plain southwest of Fitzgerald on August 17, 1928, 
and this was not looked upon as an unusual year. The autumn flora, typified 
by the goldenrods and asters, and by the ripening of the fruits of rasp- 
berries, dogwoods, roses, moose-berries, and blueberries, is well advanced 
by the third week in August. Throughout the summer there is a notable 
“ telescoping ” of the seasonal aspects of the flora. Calypso has been found 
in flower as late as June 26, and goldenrods as early as July 19. 
Records of rainfall are scanty, but indicate that during June, July, 
and August there are from 4 to 6 inches (Table 2) . Snowfall for the whole 
year averages between 34 and 53 inches in different localities (Table 3). 
As suggested above, the presence of the larger lakes has a slight 
ameliorating influence upon neighbouring climatic conditions. Monthly 
mean and absolute minimum and maximum temperatures for January and 
July, recorded at Chipewyan, Vermilion, Fort Smith, Hay River, and 
Resolution, when averaged over a period of ten years (1917-26) (Table 1), 
indicate that in winter lower temperatures are experienced at Fort Smith 
and Vermilion than at settlements on the lakes. Cool periods in summer 
reach lower temperatures inland than on the lakes, whereas warm periods 
in summer tend to be warmer inland. Of the two inland districts, Fort 
Smith consistently shows less fluctuation than does Vermilion, probably due 
Table 1 
Table of Temperatures Averaged over a Period of Ten Years , 1917-1926 
— 
Chipewyan 
Vermilion 
Fort Smith 
Hay River 
Resolution 
Monthly mean minimum. . 
/Jan. 
— 19-6 
-24-5 
-24-0 
-22-4 
-22-4 1 
(July 
51-1 
46-1 
46-7 
50-0 
51 -2 
Absolute minimum , 
/Jan. 
-49 0 
-56-1 
-53-9 
-49-4 
-47-9* 
(July 
35-3 
33-2 
33-3 
38-4 
40-0 
Monthly mean maximum . 
/Jan. 
- 2-1 
0-3 
-7*5 
— 4.32 
-8 6 1 
(July 
72-8 
74-9 
72-8 
68-1 
68-6 
Absolute maximum 
/Jan. 
26-2 
29-8 
19-2 
25-1* 
15-5 1 
(July 
86-4 
88-3 
88-1 
86-8 
83-4 
1 Averaged over seven years (1920-26) due to lack of records. 
2 Averaged over nine years, records for 1918 being absent. 
