This is real time radiation data collected via the System for Prediction of Environment Emergency Dose Information(SPEEDI). You can search by prefecture.Note that on March 16, 2011 23:50 (JST) (Japan Standard Time) : Not surprisingly, Miyagi and Fukushima are completely N/A, as every single reading is Under Survey, also known as censored .nGy/h (nano- Grays per hour) Updated[ad#468x60-ad]