The stock EffClouds.class treatment of rain sound is to limit it to months 4 through 10 (nominally April through October, if the stupid one-digit offset of the month is corrected.)
Some time ago I added an additional check to see if the map's CAMOUFLAGE entry was PACIFIC, CBI or DESERT, whereupon the rain sound would be heard at all months.
But this is no great solution. It just occurred to me that a more universal test should be the value of temperature at seal level. I just added a check to see if this is > 0, and if so the rain sound is heard, no matter the month.
Is there any potential pitfall with this reasoning? Is the graphical representation of precipitation as snow flakes or streaks of rain decided by the sea level temperature threshold of 0.0C?