The difference between digital and analog thermometers is night and day. Many of those round dials are calibrated poorly and don't respond at all to temperature fluctuation. Thus making them up to 10* off in either direction.
Digital thermometers aren't expensive. Many users here (myself included) swear by the accurite digital weather station. It is sold at almost all home depots and walmarts and sometimes at lowes. It is generally around $10-12. It measures temperature with a probe and humidity and temperature at the unit making it an all in one device.![]()