That would be too far away to see it based on the curvature of the earth.
However, you could see the glow on the horizon at the time of the blast.
9.5 square miles
the full range of an atomic bomb (not just blast range) is 20 square miles
No, Most atomic bombs have a blast distance of 40 miles. By. Husky Pratt
See: Atomic bombing of Hiroshima and Nagasaki.
Depending on the blast wave, an A bomb could do damage for up to five miles. The Atomic bombing of Nagasaki and Hiroshima in 1945 left no standing buildings for two miles in all directions.
66,000 people were killed and 69,000 injured by a 10-kiloton atomic explosion caused by the dropping of little boy at Hiroshima. The area of total vaporization from the atomic bomb blast measured one half mile in diameter; total destruction one mile in diameter; severe blast damage as much as two miles in diameter. Within a diameter of two and a half miles, everything flammable burned. The remaining area of the blast zone was riddled with serious blazes that stretched out to the final edge at a little over three miles in diameter.
30 miles.
An atomic bomb can approximately destroy 100 square miles.
The bomb dropped over Hiroshima happened to weigh 8,000 pounds and contained destructive power equal to 12.5 kilotons. The area of total vaporization from the atomic bomb blast measured one half mile in diameter; total destruction one mile in diameter; severe blast damage as much as two miles in diameter. Within a diameter of two and a half miles, everything flammable burned. The remaining area of the blast zone was riddled with serious blazes that stretched out to the final edge at a little over three miles in diameter. "It seems to be the most terrible thing ever discovered, but it can be made the most useful" -Henrry Truman-
square miles and radius have different units
6 miles
The blast would have killed anyone within 30 miles or so.