- Create a table with your data, listing the year first, then the mean temperature, and finally your error measure. (average minimum temperature in December from http://weather-warehouse.com/WeatherHistory/PastWeatherData_Amherst_Amherst_MA_December.html ; error is created for our purposes)
2. Highlight the first two columns (including the headers). Go to the insert tab and select the first option under the scatter graphs.
3. Format your graph.
4. Go to the Design tab > add chart element>Error Bars>More error bar options.
5. A “Format Error Bars” window will open to the right. Select Custom>Specify Value. Highlight your Error column (here standard error) for both the Positive Error Value and the Negative Error Value.
6. Click okay and then delete the horizontal error bars.
7. Format as with all graphs.