I don't know the specifics of Albury, but a 15 degree change...

I don't know the specifics of Albury, but a 15 degree change isn't crazy depending on what else was happening to create the outlier.

Certainly you can change by 15 degrees and keep a 1 degree error confidence level under many circumstances I can think of.

Click on the .co.nz link I put up in my previous comment and look at charts Wellington Temperature 1-4 to see if you can understand why.

By the speed of your response it's obvious you didn't do that.