Have you heard of Global Dimming? (hot, temperature, days, Canada)

[ColdCanadian]

I wonder if this is true. Interesting read. Especially about after September 11th, scientists were able to measure the difference of removed airplane contrails (exhaust) from the sky and its effects on temperature. There was an increase in diurnal range of 1 C/1.8 F over a wide area. These types of particulates limit the visible and infrared light, but don't affect UV as much. This could be partly why I always thought the sun in Canada wasn't hot enough... when I lived near the biggest airport in Canada. Also says this effect is supposed to be at its greatest at the mid-latitudes in the northern hemisphere.

Global dimming - Wikipedia, the free encyclopedia

[Bottletree]

I have heard about this too. Just a few weeks ago I read in a book how right after September 11, while air traffic was suspended for two days. Temps were 1-2c higher than normal. So I would say it does have a slight cooling effect from the contrails.

I was dissapointed the last two weeks because it was hazy/smoky with no clouds in the sky. Blocking the uv.