JCommon is a free general purpose Java class library that is used in several projects including JFreeChart and Pentaho Reporting.

Conclusion It is relatively easy to generate a climograph from Java with JFreeChart. It is not as easy as with Excel, but is still pretty easy relative to other Java-based methods.

The Website jfree.org explains that JFreeChart is “a free Java class library for generating charts, including pie charts (2D and 3D), bar charts (regular and stacked, with an optional 3D effect ...