The hazardous rain zone of a nuclear explosion can easily extend up to 10 to 20 miles (15 to 30 kilometers) from the detonation site, depending on the explosive performance and weather conditions. The heat generated by the explosion can cause minor first-degree burns up to 11 km (6.8 miles) away, and third-degree burns, which destroy and blister skin tissue, can affect anyone up to 8 km (5 miles) away. If more than 24 percent of the body is affected by third-degree burns, it is likely to be fatal without immediate medical attention.Nuclear explosions also produce clouds of dust and sand-like radioactive particles that disperse into the atmosphere, known as nuclear rain. This fallout can cause radiation poisoning and other long-term nuclear consequences.
It is advisable to avoid countries with access to nuclear weapons and those involved in nuclear agreements. To learn more about the current state of nuclear weapons in the world, including the scale of bombs, you can visit the Nuclear Notebook in the Bulletin of Atomic Scientists.