I was not referring you to that chart on that page but more the chart for dry to sweet wines. I have no idea what the hell they are talking about with that chart, its way off scale. the difference is usually about .001 for approx each 7* off 60* which is very minuscule. I was referring to a chart that came with everyones hydrometer. Here is a typical temp chart that would come with your hydrometer.
View attachment Hydrometer Temperature Chart.doc
View attachment Hydrometer Temperature Chart.doc