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. Tip to 1911 the highest temperature 

 recorded was 98. 6, but a period of heat during the 

 first few days of July, 1911, broke all records, an( 

 86 



