Used to hold the information that feeds the Webtags#Monthly for the 'thismonthT.htm' web template.
These lows and highs and their timestamps can be seen (in Cumulus 1) by picking the Highs and Lows - This month screen from the View menu, see screenshot above. Like alltime.ini the file has section headings with lists of properties (attribute = value). For more information on this file see in the Cumulus help file, in the section “Data log file format”. In Cumulus MX, at the end of each month, the final month.ini for that month is renamed monthYYYYMM.ini (where YYYY denotes the year using 4 digits and MM denotes the month using two digits) e.g. month201703.ini, thus ensuring that statistics for all past months remain accessible. (There is no facility to achieve a similar retention automatically in Cumulus 1, although all the information can be generated by doing calculations from the relevant lines in dayfile.txt and those calculations are very easy to code in SQL if the daily summary is available in a database).
The diagnostic logs in the 'diags' sub-folder record before and after values for updates to highs and lows for monthly and annual extreme records, and can help if this file is corrupted by a false extreme. The stored values can be corrected (in Cumulus 1, there is no editor in Cumulus MX) using the This month's records screen on the Edit menu. Date, Time and Decimal formatting is as per your regional settings on the PC running Cumulus. If you cannot find the file see this FAQ. With MX, you would need to use an external text editor that does not add any additional control characters (see forum for suggestions).