In conversations about war it is hard for most Americans who have never been in war to envision anything other than the carnage of 9/11. Effects of a nuclear blast, from the smallest to the largest can be estimated using Alex Wellerstein’s NUKEMAP.
Below are three screenshots from sample maps. The key for the blast radius circles is as follows:
BRIGHT YELLOW–Fireball Radius-Maximum size of the nuclear fireball; relevance to lived effects depends on height of detonation.
RED–Air blast radius-20 psi overpressure; heavily built concrete buildings are severely damaged or demolished; fatalities approach 100%.
GREEN–Radiation radius-500 rem radiation dose; between 50% and 90% mortality from acute effects alone; dying takes between several hours and several weeks.
GRAY–Air blast radius-4.6 psi overpressure; most buildings collapse; injuries universal, fatalities widespread.
PALE ORANGE–Thermal radiation radius-Third-degree burns to all exposed skin; starts fires in flammable materials, contributes to firestorm if large enough.
Use the link above to try it on your own hometown.