For motorcycle travel across Canada the summer should be the ONLY season you consider .Any earlier or later than the beginning of May and late September and you will run a good possibility of getting miserable weather with cold and rain or sleet and snow especially the farther north you get.Early May and late September can be rather cool in southern Canada. This is not saying that you may not encounter some wonderful riding weather in spring and fall in the southern regions of Canada, but it is never certain what the weather will do. Us locals have the advantage of getting out for a ride when it is nice and leaving the bike in the garage if it is lousy weather. As a tourist who has brought a bike in as his only mode of transport you do not have that option, you either must suffer through a miserable or dangerous ride or sit it out in a hotel, all the while draining your bank account and available time.
Summer pretty well is a safe bet for acceptable weather , but even then it can vary greatly from day to day , depending on where and how fast the low pressure systems move across the country.
The regular variation of weather is a certain predictable pattern- the highest temperatures during summer, ratcheting down to the deepfreezes of winter then gradually back to milder and summer again. This is a 100% safe prediction, only the details of time , duration and intensity vary.
Temperatures will in summer always be mild. Do bring rain gear and a few layers to keep warm when a cold air mass comes down from the north, and especially if you plan on doing the northern parts of the provinces, the Yukon and the sub - arctic. Even there you may encounter some very nice warm days of up to 30C range, but it might also be wet, chilly, frosty nights even in June,July and August.
If you are fortunate you may encounter what by local standards is considered a ¨heat wave¨ , temperatures of above 33C for a few days--- it does happen. And then the radio and TV weather reporters turn up the hype and everybody starts whining and bitching about the heat and humidity .Because they have all been sitting around in airconditioned offices and cars and don´t know what real humidity and heat is they forget about the winter weather they were complaining about only a few weeks earlier.

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http://advrider.com/index.php?thread....207964/page-5 then scroll down to post #93

for Sweden as well.
Take out the local canadian names and you have a description on biking in Sweden.