According to our research of Iowa and other state lists there was 1 registered sex offender living in New Vienna, Iowa as of July 30, 2016. The ratio of number of residents in New Vienna to the number of sex offenders is 425 to 1. Nearest city with pop. 50,000+: Dubuque, IA (22.0 miles , pop. 57,686). Nearest city with pop. 200,000+: Madison, WI (94.5 miles , pop. 208,054).