Next time we see a forecast for -1°F and windy, we’ll know exactly how to dress. That’s how cold it got on an early-season Colorado snowshoe trip, and it turns out those mittens mom bought keep us warmer than we expected. Also, our too-big 15°F bag started feeling chilly with lows around 35°F, and that mesh-walled summer tent didn’t hold in our body heat at all on a 33°F night.
You could say this level of temperature precision is just for geeks, but we love having the hard data to be able to match the forecast to our personal preferences and gear. It’s all because we’ve been carrying the Drop, a weather logger the size of a Double Stuf Oreo. This nifty gadget, which runs on a watch battery, takes and stores a temperature reading every few minutes (you set the interval), then downloads it to a smartphone app (iPhone only at the moment; Android coming). As soon as we started carrying the Drop, we became addicted to the data, especially overnight lows and daytime highs.
The D1 logs just temp; the D2 ($149) also senses humidity, heat index, and dew point. You can connect via Bluetooth even without cell service, and the app lets you export data to a spreadsheet. Nitpick: The only way to stop logging is to remove the battery (which lasts about four months), so we have lots of data about our closets.