How Far From a Nuclear Blast Do You Need to Be To Survive?

It depends on the direction of the wind at the time of the strike. After a nuclear explosion there is a phenomenon known as fallout, which is when the radioactive material from the blast falls to the earth as dust. This can blow around with the wind. Fallout can create radiation sickness. The closer you are to the blast, the more likely you are to get hit by fallout.

You are less likely to get hit by a nuclear blast if you live inland. Why transport a nuclear device 800 miles inland when you could detonate it at a coastal city? Additionally, a missile flying inland is more likely to get taken down by defense systems.

You are probably safer if you live upwind to a strategic site. Because the Jet Stream usually flows from East to West or North to South, you are more likely to avoid a fallout when you are North or West of a strategic target. 100 miles is a very fair distance. At even 20 miles upwind of a nuclear blast, you could escape both damage and sickness. Look at the extent of Nagasaki and estimate 2-5 times the distances.

anonymous answered:
Today's nuclear weapons (during the Cold War they were up in the 10 megaton range) are anywhere from 500 kilotons to 1 megaton (Hiroshima was 13-14 kilotons). Smaller "suitcase" nukes probably range only up to 20 kilotons if in reality past 5 kilotons.

Like one poster pointed out, there are too many variables. If you did live 100 miles from a major city hit your chances are excellent for survival as you are too far away from the blast/initial radiation effects and you have a random chance of wind direction for fallout and this depends too on air-burst (above the city) or ground-burst which creates heavier and more lethal fallout.

The big variable would be if this was a mass nuclear attack or a single one going off for counting medical aid, supplies and secondary casualties. Most a-bomb casualties in Hiroshima and Nagasaki were due to collapsing buildings and flying debris rather than being vaporized or receiving high doses of radiation.

Bobofthe answered:
You would survive the blast at 100 miles. Even 50 miles. Surviving the radioactive fallout would depend on the wind direction. The blast zone depends on the power of the weapon. Hills between you and the city would help. A blast on the ground would be less dangerous than an air burst. Another advantage to country living.

cbjack answered:
You would survive the initial blast and if you were in a hardened structure you'd survive the heat wave that follows. The next thing to worry about is which way is the wind blowing and will you be in the way of what is called "fallout". If you are in the way you could survive for a little while but you'd get sick from the radiation.