NATURAL HISTORY, TORONTO REGION 
during April, are now practically over, and with 
leaps and bounds vegetation goes forward. By the 
15th day most of the spring wild flowers are in bloom 
and many trees are in full leaf. About'ten days 
later horse chestnut, lilac and apple are in bloom, 
and incubation by migratory birds is well on the way. 
The average date of the last spring frost is May 4th. 
The warmest May on record was that of 1911, with 
a mean temperature of 61°.2, and the coldest that of 
1867, with a mean of 46°.5. It is not uncommon in 
this month for the daily maxima temperatures to 
exceed 70° for spells of a week or ten days. 
One of the outstanding features of the Toronto 
summer is the fact that wholly overcast and rainy 
days are of rare occurrence, the rainfall occurring 
in showers and thunderstorms, while days of bright 
sunshine are numerous; in fact, from the middle of 
June until the end of August one may almost count 
on days of at least part sunshine. There is an aver- 
age of 791 hours of sunshine in the three months. 
By May 20th the normal daily temperature has 
risen to 53°.5, with an average daily maximum of 64° 
and occasional days of 80°. June has an average 
daily maximum of 72°, July 78°, and August 76°, 
and during the first ten days of September it is still 
above 70°. Spells of great heat occasionally occur, 
but temperatures of 90° are not of frequent occur- 
rence. Up to 1911 the highest temperature ever 
recorded was 98°.6, but a period of heat during the 
first few days of July, 1911, broke all records, and 
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