What would nuclear fallout be like?

In the event of an all out nuclear war, we may suffer from a "Nuclear Winter". The sky will turn murky and dark. The sun will not shine for hundreds of years, and every food or water source caught in the mist of the nuclear fallout will become irradiated or incinerated. Come Winter, everything will die off due to extreme freeze.

For limited tactical use of nuclear weapons the results will be less dramatic. None of the tests of nuclear weapons or the deployment of such systems at the end of WW2 caused any impact on the weather. Som radiOSactive isotoes were noted in downwing rain and snow,