1906-7.] CLIMATE OF YUKON TERRITORY. 293 
In March the monthly average at Dawson is 5°; on an average 
zero is reached on nineteen days and —20° on eight days, while — 40° 
may be recorded, but it is unusual, and —50° has not been recorded 
_ since March, 1897. The temperature in this month frequently rises’ 
above 32° and 50° is occasionally reached. The more southern stations 
show a mean temperature about 10° higher than Dawson. 
April may well be termed the first spring month as there are few 
days on which the thermometer does not rise above 32° and 50° is 
occasionally recorded. The average mean of the month is 28° and in 
some years the temperature does not fall to zero. The precipitation 
is usually in the form of snow, but rain sometimes falls. In this month 
the average temperature is very approximately the same throughout 
the Yukon. 
May has an average mean of 46° at Dawson and there are few 
days on record on which the temperature has remained below freezing 
all day ; 50° or higher is reached on twenty-four days: 60° on nine days 
and there are many records of 70°, notably in the years 1905 and 1906 
with ten days of 70° in the former and seven in the latter. The average 
date of the last frost is the 19th. 
The ice on the Yukon at Dawsor usually breaks up between the 
15th and 2oth, but not until a fortnight, or three weeks later, on Lake 
Laberge. The season is now further advanced in the north than in 
the south and it is not until the end of August or early September 
that the mean temperature is again as low as at White Horse or 
Tagish. 
June is a perfect summer month and with practically no darkness 
and on fair days nearly twenty hours of bright sunshine, vegetation 
advances very rapidly. Frost, while not unknown in this month, is quite 
unusual. The average daily maximum temperature is 70.5° and the 
daily minimum 45.2°, giving an average mean of 57.5°; 70° is on the 
-average reached or exceeded on sixteen days; 80° or higher on four 
days and 90° was recorded in June, 1899. 
July weather in Dawson is quite fairly comparable with that in 
the same month in southern Alberta and with the longer days growth 
is probably more rapid in the former locality than in the latter. The 
average mean temperature is 60.4° with an average maximum of 
72.7° and an average minimum of 48.1°. There are very few days on 
