Software - FWI Calc

Current Stable Version: (19th March 2020)


FWI Calc is a small Windows® 32 bit platform application that allows Fire Danger Indices (FWI) to be calculated from data obtained from private weather stations (a small data file that most weather station software is capable of producing is parsed by FWI Calc once a day). It is Freeware.

Important Notes

  • PLEASE NOTE: There has been a very long break (3 years) between updated versions. Its author will attempt to release updated versions from time to time, though users should not expect the software to be fully supported. Errors encountered or improvement ideas can be forwarded to
  • MicroSoft continues to upgrade its security system on All operating systems from Windows 7 - Windows 10. This may prevent the Help File (fwicalc.chm) opening correctly. Use Windows Explorer or My Computer to go to the Help Folder where you installed FWICalc. Right-click on the fwicalc.chm file, select Properties. You should see an unblock button near the bottom of this dialog - click it - the file should now work. Failing this - there's a PDF (1.7MB) version available Here.

What's New...

  • A HTTPS (SSL) file can now be utilised as the weather input file. Two new DLL files are required to make this work.
  • Minor change to Title in "FTP File Select" dialog to indicate that only directory is required for server field.
  • Have been working on the various challenges that the BKDI index throws up. Have made it more accurate in this build.
  • Have attempted to make the FWICalc database file more robust in terms of version control, and not allowing the user to import corrupted files.
  • FWICalc will now read the Weather Data File every 15 minutes; this allows it to determine Temperature, Humidity and Wind Speed as the day progresses to its "Peak" - it will record the Maximum Temperature, the Humidity and Wind Speed at that time, the time this occurred, and use this data in FFDI & GFDI indexes (and optionally in CBI, FMI and Angstrom indexes). Data, Parse Files and Graphs will be updated if there is change. The FTP File system has also had a change to assist; instead of needing to set times (you still can), you can Select "Upload Files Automatically" - all files that are activated will be transfered after a automatic change has occurred in the database (ie. at midday, then every 15 minutes until Maximum Temperature increases no further). Note: This change relies on the Weather Data File being updated by your weather software regularly (VWS and Cumulus created files do this, but Custom Data Files may need you to change the update schedule to every 15 minutes in your weather software). This process does not affect the FWI indexes (FFMC, DMC, DC, ISI, BUI, FWI), they still rely on data read at midday only as the algorithms already account for this.
  • Email and Alarm system now incorporated. Can send daily data with any auto-update or at desired time (12:00hrs - 20:00hrs), can attach FireBoard graphic. Alarm system also included (Fire CrossOver, A Index meets desired value). Alarms can be set up to email as well.

Free Downloads...

This is Freeware, it comes with no warranty or user guarantee, however I do guarantee it is virus/spyware free if uploaded from this site...

THE WINDOWS INSTALLER (MSI) MAY ASK YOU TO REMOVE THE PREVIOUS VERSION BEFORE INSTALLING THIS LATEST PACKAGE (All your data files and settings will be preserved) - Go to Start Menu / Settings / Apps - Click on FWI CALCULATOR - Click on Uninstall.

Operating System        Download        
©Windows 7/8/10 (32 or 64bit) (Stable Version

FWI Calculator has not been specifically written for these operating systems, however the current version does appear to operate without error. It is suggested to install FWI Calculator to a folder independent of the default "Program Files" folder eg. C:\FWI (If you are using the Windows Installer Package to install choose a new installation folder when given the opportunity). If the application does not run as expected, right-click on it's shortcut, choose Properties, select the Compatibility tab, and in Compatibility Mode select Run As - Windows XP (Service Pack 2).

WINDOWS 64 Bit Systems: FWI Calculator may not function on some 64 bit operating systems (no fixes are available)! It is suggested to install FWI Calculator to the "Program Files (x86)" folder (eg. C:\Program Files (x86)\FWI). This should allow the program to run with 32 bit emulation. Failing this try installing in its own separate folder (eg. C:\FWI) .
32 bit Windows Installer Package (5.64Mb fwi_calc111.msi)
©Windows 98,2000,XP,Vista (32 bit) (Stable Version 32 bit Windows Installer Package (5.64Mb fwi_calc111.msi)
©Windows 95Not Available
©Apple Mac or LinuxNot Available
CORRUPTED FILES? (For use with Current Version Only!)
You can download them individually here. You MUST download the FWI.exe file, and the four DLL files (5 files) to avoid any compatibility issues. All files except the Help File (fwicalc.chm) should be placed in the main folder (eg. Program Files/FWI) where you installed FWICalc, the Help File should go in the help folder (eg. Program Files/FWI/help).
FWI.exe (4.78MB)
fwimath.dll (423KB)
fwidat.dll (1.3MB)
libcrypto-1_1.dll (2.27MB)
libssl-1_1.dll (706KB)

fwicalc.chm (1.03MB)

The Windows Installer Package will guide you through the setup process.

Help AvailableClick Here to download a PDF (1.7MB) version of the Help File for FWICalc.

Weather Software Web Tag File Downloads...

Note: These files have not been tested on all systems; the "Date Tag" may still cause issues on some systems. FWICalc is looking for mm/dd/yy or dd/mm/yy depending on your countries date format (Year can be 4 digit. Separators can be / or - or .). Some weather software provides individual Day, Month and Year tags so you could create a date tag that consistently works eg. Cumulus: <#month>/<#day>/<#year>.

Right-Click on the links below and choose "Save As"...
24 Hour Rainfall Used (Semi-Colon delimiter)
Weather SoftwareDownload
Weather Displaywd24_input_values.txt
Cumulus (1.9.1+)cu24_input_values.txt
Wetterstation (de)ws24_input_values.txt
Annual Rainfall Used (Semi-Colon delimiter)
Weather SoftwareDownload
WeatherLink (Davis)wl_input_values.htx
Weather Displaywd_input_values.txt
Wetterstation (de)ws_input_values.txt
Example HTX file containing all Web Tags
(to be used as "Input File" for web parsing)
Example Web Input Filefwi1.htx (right click to save)

Live Example (web outputs for Arthur's Pass)...

Wind Speed
Peak Humid
Peak Wind
v11.1.2.111 (18-03-2020)

Enabled "Check for Updates" from within application. This will take you to this webpage if an update is available. You must download the 32 bit Windows Installer Package (5.64Mb fwi_calc111.msi) to upgrade. Repaired the Fireboard so toggling the Danger Text from Uppercase to Title Case now functions. Enhanced the applications error logging procedure so its more useful to the programmer. Other minor changes to prevent errors being raised needlessly. Windows 10 compatibility tweaked.

v11.1.1.110 (14-03-2020)

Allowed ssl (https) input files to be used. Two new dll files must be in the root directory of FWICalc.

v10.5.2.109 (27-03-2017)

Included a Windows version sensor, and tests for Windows 10 compatibility during setup.

v10.5.1.108 (21-03-2017)

Changed code that reads data input file to do some further cleaning of spaces and line-feeds to assist MeteoHub users.

v10.4.1.107 (11-05-2016)

Six critical data files can now be automatically backed up. Go to FWI Setup/Application Settings to select location to save.

v10.3.1.106 (24-02-2016)

Some minor changes required for Windows 10 compatibility.

v10.2.1.105 BETA (13-06-2015)

Minor changes required to previous BETA.

v10.0.0.104 BETA (31-10-2014)

Enhanced Fireboard adjustments. Allowed user to define danger thresholds for Angstrom, GFDI and FFDI indexes. This build will be reissued as Build 105 once it passes muster.

v10.0.0.104 (16-10-2014)

Some minor fixes and improvements.

v9.9.1.97 - (1-06-2013)

Changes to way BKDI is calculated (modified Crane 1982 algorithm). Created Email Alarm system. FWICalc can now read weather data file every 15 minutes and use peak daily values in FFDI, GFDI and optionally in CBI, FMI and Angstyrom indexes. Have changed BKDI index so it now stores as a fractional number (displays as integer however), this creates more accurate calculations and conversions.

v8.8.1.96 (21-02-2013)

Repaired some bugs pointed out.

v8.7.3.95 (07-02-2013)

BKDI now displays and accepts values as per your units rainfall setting (mm/in). Metric range 0-203, Imperial range 0-800. If you have version and wish to upgrade prior to next automatic release upload FWI.exe from the Corrupted Files section and overwrite this existing file in your FWICalc installation folder.

v8.7.2.92-94 (05-02-2013)

Added FFDI, GFDI, BKDI & DF indexes. Revamped main window user interface. Build 93 removes a bug notified when FWICalc is minimised to taskbar and automatic calculations proceed (Cannot focus non-visible window), also includes a Fuel Load Estimator for those folk that asked.

v8.3-6.0.86-91 (BETA 20-01-2013++ Not released)

Moved FWI Math and some Data File functions to DLL (Dynamic Link Library). This reduces some memory usage, and allows the FWI Math functions to be exported to other software. Fireboard now shows indice used and it's value, and title will auto-size. Cure Table can now suggest values based on hemisphere. Minor changes to Setup Page to force correct value entry.

v8.2.0.85 (30-12-2012)

Very minor upgrade to remove some redundant code, and fix my spelling errors. Don't worry if auto-updater is not asking you to upgrade to this version. If you really want it - upload FWI.exe from the "CORRUPTED FILES" upload section and place it in the main FWICalc folder.

v8.1.0.84 (26-12-2012)

Complete revamp of database file format. New fire indexes (Angstrom, FMI) and calculation of Australian Code Red index (from FWI). Fireboard now allows for 6 segment Code Red board, with segment colours selectable via the colour scheme dialog (ie. FWI, FWI Code Red, CBI & Angstrom). Main page window now allows for selection of shown indexes (date is still compulsory). ^fwitable^ now allows for selection and order of indexes plus more flexibility in formatting. Print routine also allows for selection and order of indexes. Multiple new webtags available.

v7.6.1. Builds 81 - 83 (01-12-2012)

All BETA releases with tweaking of ^fwitable^ Webtag format.

v7.6.0.80 (03-11-2012)

Incorporated 2D Fireboard graphic. Minor changes to Import/Export functions. Minor fixes.

v7.5.0.79 (06-08-2012)

Redesigned Import/Export feature to make it less memory intensive when used with large input files. Changed FTP Server setup procedure to prevent log-in failures with some servers. Extended FTP log to provide more detail information. Found solution to errors caused by VWS data files not localising list or decimal separators (data.csv). Other minor changes.

v7.4.0.78 (26-05-2012)

Windspeed units/input can now be m/sec or ft/sec. Both VWS & Cumulus data files can now be directly imported into FWICalc. Numerous other adaptions and changes to take advantage of the new compiler functions.

v7.3.0.77 (27-02-2012)

Completely transferred application production to new compiler language. This version never released as always in TEST BETA.

v7.2.0.76 (14-01-2012)

Restart Button now inserts all missed days at end of FWI Data File with Fudge values. Information Dialog now available that shows information / statistics of FWI Data File. FDC values (FFDC,SFDC,GFDC) have options in both the Application Settings and Web File Setup to be shown as kW/m². PS. This is the last of Holiday Season updates - Cheers!

v7.1.3.75 (07-01-2012)

Included CSV File Import function. Repaired bug that disallowed negative temperatures on some operating systems. Removed a few caution screens that were no longer required.

v7.1.2.74 (5-01-2012)

Interim Update: Provided CSV Export function. Repaired time fault reported on some Windows 7 platforms. Changed editing technique to double-click on data grid. Fixed minor issues reported by users.

v7.01.73 (12-10-2011)

Maintenance update. Fixed minor issues reported by users.

v7.00.72 (10-06-2011)

Forest type selection is now available in setup; this will make FFDC more accurate in specific environments. Forest Type, last GFDC,SFDC & FFDC kilowatt intensities are now available in webtags. Will make them available in web table in next release. Fixed bug in DMC winter calculation.

v6.18.71 (28-05-2011)

A FWICalc Restart button has been added to front-page to assist in getting it going again after data has stopped being processed (to be used if you don't want to put missed day data in manually).

v6.17.70 (14-05-2011)

Fixed an issue with the calculation of the monthly CBI value, and modified Graphing Package to make 3D graphs more robust. Numerous WebTags added for current year highs/lows.

v6.16.69 (3-05-2011)

Fixed error in FTP component causing freeze up if broadband connection fails during transfers. HTML Table Column headings can now be edited by the user & up to 100 rows of data permitted. Further WebTags added.

v6.15.68 (7-01-2011)

Activated automatic update function in Help menu (Check for Updates). This will automatically upload & install FWI Calculator components.

v6.14.67 (6-01-2011)

Included setup function to account for winter ground snow at weather station. Also modified HTML Table function to allow for full expansion of table headings. Fixed some minor bugs in the Environment variable setup routine (scrub must have a height > 0).

v6.13.66 (14-10-2010)

Corrected error that prevented temperature appearing in some webtags.

v6.12.65 (22-09-2010)

File fwiweb.xml is now created irrespective of File Settings so it can uploaded using 3rd party FTP software.

v6.11.64 (12-08-2010)

Corrected bug that prevented decimal separator (as comma) on some machines. Introduced more HTML web tags. Help is now available online as website or PDF file.

v6.10.63 (1-08-2010)

Fixed error in CBI recalculation routines (only effected imperial temperature inputs).

v6.00.62 (4-07-2010)

More issues with Windows 7 implementation patched, these have caused issues with RAS (Dialup modem) connection issues on all operating platforms. Users may need to reapply their RAS settings.

v6.00.61 (21-06-2010)

A problem associated with Windows 7 & some 64bit systems has been creating a "Previous day data not found!" error has been reported by some users - this patch should (hopefully) resolve this.

BETA v6.00.60 (10-06-2010)

Revamped the FWI Setup process (hopefully more intuitive, and self checking). Removed some memory overhead, and fixed some reported bugs.

v5.23.58 + 59 (31-05-2010)

Application is now portable; more than one instance is allowed (from differing folders only) so multiple weather stations can have FWI data processed. Repaired 32bit installer error.

v5.22.57 (24-05-2010)

Removed some minor bugs. Added ^parsetime^ as a new miscellaneous web tag. Changed old 16 bit installer for 32 bit MSI Windows Installer.

v5.22.56 (05-12-2009)

Introduced HTML Help for Windows 98, XP, Vista Users. FTP Log, and Minimise to System Tray now available on start up.

v5.21.55 (29-11-2009)

Can now upload a preformatted XML file to your website, that in turn can be uplifted by this website and utilised in Google Mapping services etc. This version had an introduced problem of "double parsing" weather files.

v5.1.54 (05-11-2009)

Revamped the database to future-proof it (please note that all databases are modified in the installation process - your original data is preserved in file - default53_bak.fwi). Added further facilities in graphing package, GIF images can now be saved with a transparent background.

v5.0.53 (1-11-2009)

Fixed notified bugs (CBI Danger Code & Graph Recall Button Error).

v5.0.52 (29-10-2009)

Entirely replaced graphing package, can now create & FTP graphs to server. Fixed the "Exit" bug! Revised entire program so it should run on Vista.

BETA v5.0.51 (25-10-2009)

Chandler Burning Index now calculated, new graphing package, new Internet / FTP system, new HTML parse tags, fixed bugs.

v4.1.50 (14-06-2007)

Included method of changing Fire Danger Rating colors (Edit/Fire Danger Color Scheme).

v4.1.49 (04-05-2007)

Broadband connection now selectable in RAS/FTP setup dialog.

v4.1.48 (15-04-2007)

Fixed bug effecting HTML table units displayed.

v4.1.47 (05-03-2007)

Fixed some user identified bugs. Enabled the "GRASS CURE TABLE" feature.

v4.1.46 (23-05-2006)

Found a memory leak that needed patching, also reduced the CPU load during processing functions. Removed some redundant buttons. Added the "FUDGE" feature, allows data to continue be written to the data file even if the wx stn software has crashed and stopped creating input files.

v4.1.45 (19-05-2006)

Just some subtle improvements to the graphing package - can now change the colour of most graph elements, can now swap which series is shown in front (handy on area graphs), changed the graph print routine so you can choose printer & print properties, you can now show a red band on the graph which indicates high-extreme fire danger for the chosen indice.

v4.1.44 (17-05-2006)

Wouldn't you know it as soon as I release the new version someone points out a bug. The ActiveX bug in the installer program has been remedied (I hope). I have allowed for selectable delimiting characters in the Weather station input files (default is Line Feed).

v4.1.43 (16-05-2006)

YES there has been a huge gap in the development time. That is because a cooked PC and corrupted backups meant I lost the original source code for the project. I have now rewritten, and reverse engineered the 37,000 lines of code used to create this application. It may look the same, but builds 1..42 have seen a dramatic change in the way it handles the algorithms and other routines. RAS & FTP procedures have been completely rehashed (made more simple I hope), multiple bugs fixed, unit of measurement selection added, hemisphere & country selection added, latitude & longitude now effect some indices, print feature is now enabled, the graphing package has been rewritten, plus a few other tweaks.

v4.0 (16-04-03)

Added "Start Minimised" checkbox on main entry form. This permits the application to start "off screen" which is useful if it is part of a series of applications running automatically on the host PC (such as in an automatic weather station situation).

v3.9 (31-03-03)

Added "Process Now" button to Web Options page to allow forcing of Data File processing irrespective of data already existing (use with caution). Moved "Parse Now" button on Web Options page, and limited function to only parsing files. Data File is no longer processed.

v3.8 (28-03-03)

Added 43 new statistical tags to the parse file tag list (^sta...^).

v3.5 to v3.7 (05-01-03) (Don't ask)

Allowed for extra file in Parse file routine (now x4), but now very extendable. Added Last Fire Danger Rating colour tags to parse file tag list for FF, SF & GF. Streamlined save routines and extended capability of setup routines. Added "Apply" buttons to Web Options & Graph pages to enable changes without leaving page. Sorted out Environment Set/Use default value system. Added "New" to file menu, and rehashed method of file creation.

v3.4 (02-01-03)

Corrected flaw in Display menu "year" routine. Fully automated builtin version updater for versions 3.1+. Slight changes to way display updates itself (no more added blank lines).

v3.3 (23-12-02)

Corrected occassional errors on selecting data in grid. Address data file directly for ALL values now. Save on change now automatic. Changed graphing routine so date range or last record count can be used (limit 100 records displayed). Changed web tags slightly. Only major change ^fwitoday^ becomes ^fwifwi^. This was because "todays" records may not be available at time of parsing so "last" record is displayed instead. Added "Parse Now" button on Web/Options form. If "Input File" date is already present in current records the data WILL NOT be processed, however the "Parse File" WILL be parsed as normal. This prevents Total Rainfall being corrupted. Added "Display" menu item. This allows various opitions on how many records to display in visual grid on base of main form. Year (eg. 2002) is also available. Corrected graph component to accept 100 X-Axis values. Corrected fault in parse file routine.

v3.2 (01-12-02)

Changed some terrible gramatical errors (whoops). Working on PRINT routine, harder than expected, unfinished. Provided a routine to automatically upgrade version non-compatible data files if required. Repaired fault in "Save As" routine. "Print" routine has been disabled in this version whilst I rewrite the code.

v3.1 (29-11-02)

Included algorithms for Forest, Scrubland and Grassland fire intensity (FI) and danger codes (FFDC,SFDC,GFDC). Environment input panel added to Main Page. Updated parse tags to reflect changes to available danger codes (^fwiffdc^,^fwisfdc^,^fwigfdc^) . Minor help system fixes. Revamped & simplified fwicalc.ini file creation process. Realigned, centred text, buttons, edit boxes etc (neatened the thing up).

v3.0 (26-11-02)

Incorporated FTP & Dial-up Connection procedures. Incorporated 96bit encryption routine for password storage. Revised data file storage system from ascii text based to binary random access system. Required creating two data files per profile (*.fwi = fwi data, *.fws = profile setup). Stress tested application. Simplified date format checking routines & error pickup. Repaired StringGrid TopRow bug. Repaired Fire Danger Rating bug. Repaired FTP timer bug.

v2.1 (19-11-02)

Added 2nd series overlay procedure to graphing routines. Included automatic version updater for data files.

v2.0 (17-11-02)

Designed and incorporated graphing capability.

v1.1 (26-10-02)

Added file parse and HTML table routines. Created Windows help file for application.

v1.0 (13-10-02)

First Beta version written. FWI calculations only.

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