I previously used an older version of the DS1820 outdoors, and found that it absorbed moisture and lost its accuracy over time. To get around this problem, I took a small piece of plastic tubing from a hardware store, just large enough to hold the sensor (with the wires coming out one side) and epoxied the sensor inside. I have had this outside for several years now and it is still accurate. The disadvantage is that it takes a bit longer to respond to temperature changes. Supposedly the newer versions of the DS1820 are not as sensitive to moisture, but I think protecting it is not a bad idea if it might get wet. I don't believe the temperature extremes you mention should require special consideration.