Hi Stu,
reading the post about your explanation about a blip in custom graph, I have a spike end of Feb 2013 checking the Data Viewer I can see that the monthly rain drops a number of times from 49mm back to 0 for 1 entry/line and then back to normal the following line. Correspondingly the annual rain also drops and comes back -up.
I understand I can edit it but does this explain the sike?
Gerard