Date and Year Maximum Minimum
January 5th, 1955 -18°C -28°C
January 5th, 1960 -35°C -40°C
January 5th, 1965 -29°C -38°C
January 5th, 1970 -16°C -29°C
January 5th, 1975 -31°C -41°C
January 5th, 1980 -24°C -27°C
January 5th, 1985 -8°C -11°C
January 5th, 1990 -27°C -33°C
January 5th, 1995 -12°C -35°C
January 5th, 2000 -27°C -36°C
January 5th, 2005 -8°C -16°C

What does this line graph measure?

What does it tell us?