Trying to keep both temperature and humidity just right? The Active Air Hygro-Thermometer makes it easy! This digital tool gives you quick, accurate readings of both temperature and humidity of the environment you place it, with an additional sensor that can be located outside reading the outside temperature. This thermometer also has the added feature of showing the historical maximum and minimum temperatures and humidity, so you can know what the extremes were like when you weren’t there to see it for yourself. By far the most important greenhouse accessory. It’s compact and has a clear display, making it perfect for greenhouses, indoor gardens, or anywhere you need reliable monitoring.