Rolf - An example of using user-defined rain data is shown in:
http://www.computationalhydraulics.com/swmmqa56.html There are several
other discussions of RAIN input in the SWMM-USERS archives. Here's
another example. It reads 5 minute data in decimeters and converts to
millimeters for two gages:

* #blocks RAIN
SW 2 15 16 17 16
MM 4 11 12 13 14
@ 15 h19.txt
@ 16 rain.int
@ 17 k08.txt
$RAIN
A1 rainfall
A1 2000-2001
B0 0 0 1 *delete old rainfall file
* IFORM ISTA IDECID IYBEG IYEND IYEAR ISUM MIT NPTS IFILE A
NOSTAT
B1 3 1 1 0 0 0 0 12 20 0 0 10
* THISTO METRIC KUNIT FIRMAT CONV F1 - F7
B2 5 1 1 '(5x,i5,4i3,f7.4)' 100 0 1 2 3 4 5 6 7
*
$RAIN
A1 rainfall
A1 2000-2001
* IFORM ISTA IDECID IYBEG IYEND IYEAR ISUM MIT NPTS IFILE A
NOSTAT
B1 3 2 1 0 0 0 0 12 20 0 0 10
* THISTO METRIC KUNIT FIRMAT CONV F1 - F7
B2 5 1 1 '(5x,i5,4i3,f7.4)' 100 0 1 2 3 4 5 6 7
*
$ENDP

Here's a snippet from H19.TXT:

4 2001 2 25 17 50 0.0500
4 2001 2 25 19 55 0.0500
4 2001 2 25 20 35 0.0500
4 2001 2 25 20 40 0.2500
4 2001 2 25 20 45 0.3000

Regards,
Mitch Heineman, P.E.
HeinemanMC@CDM.COM