I have an Equity Weather Station model 31215B and i was wondering if the outside wireless thermometer is waterproof .

The wireless unit that transmits to the indoor unit is weather resistant, but not immersible. Even so, try to shield the transmitter from the sun and rain, if possible. When positioning the transmitter, keep in mind that direct sunlight may cause false readings and mounting it on heat-retaining materials (like brick) will show a higher temperature, even after sunset. Avoid mounting it anywhere near things that give off heat (air conditioner units, dark exterior walls, etc.).

LaCrosse has not yet uploaded the manual for this, but you may check later at:

equitybylacrosse.com/31215

Good luck from Detroit, MI.