Why does weather dot com says that the record low for boston is -30 F degrees?

let me explain why this information is so wrong, first of all nearby cities like philly has a record low of -7, New york city around -10, worcester,ma wich averages much cooler temperatures at night has a record low of -17, even braintree that is just 15 minutes SW of Boston has a record low of -13 and besides i've been living in boston for 10 years and the coldest temperature have ever seen is about 0 degrees, so i dont think -30 is possible here, maybe in minneapolis or wisconsin but it never gets that cold here