We are gradually adding environmental radiation readings taken since the beginning of the disaster to build a clear picture of the contamination over time. Please check back frequently as this will be an ongoing project.
Greenpeace radiation readings taken in Fukushima 2011: Go to their Google Map
Greenpeace radiation readings map 2011 and 2012
CRMS – Citizen Radioactivity Monitoring Station – Non government radiation readings
Prof. Hayakawa’s radiation readings in Fukushima region. Periodically updated
US Embassy Readings March 2011
March 2011 – Radiation readings from US Embassy in Tokyo
IAEA gamma dose readings March-April 2011:
IAEA surface dose readings:
IRSN plume maps: http://frmr-jp.blogspot.com/2012/09/20113.html
Safecast radiation readings (includes links to various citizen radiation networks):
MEXT (Japan Ministry of Education) Radiation monitoring stations. Please note that these readings are for the actual location where the monitor is located, some monitors are atop multiple story buildings. The “adjusted to 1meter off the ground” reading is usually buried in fine print and is the important reading. MEXT has also been found to be decontaminating around monitoring stations or setting them on top of metal plates to make the readings artificially lower. So these readings are artificially lower than the reality at that location. http://radioactivity.mext.go.jp/map/ja/area2.html
Japan Environment Ministry Decontamination Efforts (They take readings and are supposed to be logging the before/after levels as decontamination is attempted)
Historial Radiation Readings In Japan Back To 1957: Google translated search interface version of the page
Many local municipalities maintain radiation sensors, we hope to add many of those soon.