The top red line is the highest max temp, the bottom blue line is the lowest min temp, the orange lines are the upper and lower standard deviations, and the middle grey line is the average of the mean.
Notice that since 1900 July maximum temps have been falling, getting cooler. So has the minimum temperatures in July. Getting cooler for this location.
Two baselines are needed to get the anomalies. The Max Baseline is the average of all those highest temps for the complete range of years. The Min Baseline is the average of all those lowest temps for the complete range of years. These two are then used to subtract the highest and lowest temps respectively to get an anomaly. They look like this (separate graphs because of overlapping lines):
The cooler nighttime trend is clear here.
Now we do this for all stations put together in the same manner to see what is going on collectively. Since each station has its own anomaly, there will be a range they all fall into.
So you can see clearly that for all stations in Canada, there is no trend, up or down, for July temperatures. Since that is the hottest month of the year, where is this "global warming" these guys talk about? You know, when they claim there will be more heat waves, and they blame the several thousand people dying of heatstroke in Europe in 2005 on AGW, more drought because of scorching summer heat?
It doesn't exist. There is no global warming.
February is next, the coldest month of the year.