I checked a cheapo stainless steel probe digital thermometer (UK equivalent of $8US, bought at a market stall) against a calibrated glass-mercury thermometer. They were in total agreement. Worrying about fractions of a degree is verging on paranoia, especially as most glass thermometers can't be read that accurately.(posted 8628 days ago)
Unless it's fallen out of a Christmas cracker, any thermometer should be accurate to less than 3 degrees, except, of course, those bi-metal dial type abominations.