When was the last Nuclear test occurred?

Maybe weapons testing. Great, there are sure many kinds of nuclear testing I had no idea about that.

Oh, yea there has been plenty of uses for nuclear science and technology. But for weapons testing, I believe North Korea has been doing plenty of underground testing with 'bombs' in the past decade. It was actually scary news, and super powers like the United States jumped on it asking North Korea to stop it immediately. I believe it was between 2006-2009 that they made headlines about their nuclear weapons and research. But more recently, they have been moving forward on using their nuclear research on power, I believe it was just last year that North Korea claimed they successfully achieved nuclear fission. But aside from North Korea, I believe no other countries have been testing nuclear weapons, not that the media got a hold of and letting the public know about at least. Most countries who are part of the UN are prohibited from using nuclear research for weapons and countries who are not part of the UN, will be demanded by the UN or threatened at least to immediately halt all activities.

That's true. Btw, I was asking for a confirmed nuclear weapons testing. About your comment on North Korea It's true that North Korea was testing certain nuclear weapons because it was recorded in Japan that an intense explosion really occurred in an underground site in North Korea. Because of that event the US, South Korea, Japan and nearby Asian countries were alarmed and accused North Korea of developing Nuclear weapons secretly where North Korea denies. I think the underground explosion in North Korea yielded 1Kiloton of TNT or equivalent to 1/13 the power of Hiroshima bomb. Did you hear about the current news that North Korea is now cooperating with the UN about her nuclear program. I hope they will have a positive outcome and settle the problem with regards to nuclear weapons of North Korea.

I think the largest nuclear bomb ever tested was not tested in high atmosphere. Correct me if I'm wrong but the Tzar bomb was the largest nuclear bomb ever tested yielding 58-60megatons of TNT or 5000times the power of Hiroshima bomb. Scientist later learned that atmospheric explosion is worst because in a nuclear explosion the earths magnetic field is being disrupted and at high altitudes it creates what we call electromagnetic pulse (EMP), EMP doesn't harm humans but it can temporarily or permanently destroy electronic component like Integrated Circuits (IC) on a computer (destroying the computer) or disable the cars ability to start. During 1950's and 60's EMP was not considered dangerous because it can't harm humans and only few electronic devices has IC's during those time. Later in 1990's people understand that the more high tech we are the more were vulnerable to EMP. A nuclear explosion at altitudes 300-500miles above the ground can create EMP huge enough to cover the entire area of US and cause unimaginable damage to all known electronic gadgets(computers,cellphones,cars,etc.)