Well, I don't have a snowcat but how about a freezer thermometer?
I use these as it has the sensor wired and remote (so I don't have to open the freezer to see the temp)
[ame="http://www.amazon.com/CDN-TA20-Visual-Refrigerator-Freezer/dp/B000I62FQI/ref=sr_1_16?ie=UTF8&qid=1452530392&sr=8-16&keywords=freezer+thermometer"]Amazon.com: CDN TA20 Audio Visual Refrigerator Freezer Alarm: Kitchen & Dining[/ame]