Fukushima Prefecture’s own environmental radiation pages put the air dose rate in Fukushima City at 0.10 microsieverts an hour in FY2025, against 1.91 immediately after the earthquake of 11 March 2011. The prefecture describes the current figure as about one nineteenth of the 2011 reading, and the page carrying it was last updated on 29 September 2026.
That single number is the one visitors look for first, and it does not answer the rest. Evacuation orders still cover part of the prefecture, one national highway crosses that part under a rule that treats cars and pedestrians differently, and two official pages count the remaining evacuees on two different dates. What follows is what the prefecture and the national weather agency actually publish, with the measurement dates attached, because on this subject the date is half the fact.
The FY2025 figure for Fukushima City was measured between 21 April and 16 June 2025
The prefecture builds its air dose rate maps from environmental radiation monitoring and a mesh survey. The map it labels Figure 1 is drawn from data taken between 12 and 16 April 2011, roughly a month after the accident at the Fukushima Daiichi Nuclear Power Station. The map it labels Figure 2 is drawn from FY2025 data, collected between 21 April and 16 June 2025. The page labels that map twice over: its caption and the alt text of the image both read FY2025, while the explanatory paragraph printed beneath the two maps still says Figure 2 represents data from FY2023.
Alongside those maps the prefecture plots the air dose rate in Fukushima City over time. Its text gives two values on that curve: 1.91 microsieverts an hour immediately after the earthquake, and 0.10 microsieverts an hour by FY2025. Dividing one by the other gives 19.1, which is the arithmetic behind the prefecture’s own phrase “approximately 1/19th”; the division is ours, the two values and the phrase are the prefecture’s.
The prefecture also states that the Aizu region, the prefecture’s inland west, “has returned to air dose rate levels comparable to those before the nuclear accident”, and attributes the fall in the Nakadori and Hamadori regions to natural decay of radioactive materials and to decontamination. It does not publish a single prefecture-wide number in place of the maps, which is why the maps are the artefact to look at rather than any one figure.
The comparison table the prefecture offers was measured six to eight years earlier
To put its figures in context the prefecture publishes a short table of air dose rates in other cities. Every entry carries its own measurement date, and those dates are the reason the table cannot simply be read against the FY2025 Fukushima City figure.
| City | Air dose rate (microsieverts/hour) | Date measured |
|---|---|---|
| Sapporo, Hokkaido | 0.03 | 5 March 2019 |
| Tokyo | 0.04 | 5 March 2019 |
| Fukuoka | 0.06 | 5 March 2019 |
| Paris | 0.04 | 15 October 2017 |
| New York | 0.05 | 23 January 2018 |
| Beijing | 0.07 | 25 January 2018 |
| Singapore | 0.10 | 24 January 2018 |
| Seoul | 0.12 | 25 January 2018 |
The page holding this table records its own last update as 8 March 2019. The Fukushima City figure of 0.10 comes from a page updated on 29 September 2026 and from data gathered in 2025. The two sets of numbers are therefore separated by six to eight years, and the prefecture has not restated the other cities on the 2025 basis. Any arithmetic across the two sets would be comparing readings taken years apart.
Monitoring runs on 629 posts and 2,996 real-time dosimeters
The page that carries that table, last updated in March 2019, also publishes what the measuring network consists of, and the counts are specific. 629 monitoring posts stand at public facilities across the prefecture to track changes in air dose rates. 2,996 real-time dosimeters are installed mainly where children spend time: schools, childcare centres and parks. Data from the monitoring posts and the real-time dosimeters are updated daily on the prefecture’s radioactivity measurement map.
Two further methods matter to a visitor. Places where people gather are measured with a survey meter once a year, and tourist spots are measured twice a year, the only one of the five measurement methods that page lists in which sightseeing locations are singled out. A vehicle fitted with a GPS radiation meter drives set routes, and the prefecture states that some route buses carry the same equipment and measure as they run.
Only difficult-to-return zones remain under evacuation orders, and twelve municipalities are listed
On the question of whether evacuation orders are still in force, the prefecture’s explanation page, last updated on 1 December 2025, is direct: orders have been lifted in stages as decontamination and infrastructure work progressed, and “currently, only areas that are classified as a ‘Difficult-to-return Zones’ remain subject to evacuation orders”.
The prefecture keeps a separate index for the municipalities whose evacuation areas it tracks, updated 31 August 2026. It names twelve: Tamura City, Minamisoma City, Kawamata Town, Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village and Iitate Village. Counted by type that is two cities, seven towns and three villages; the sorting into types is ours, the twelve names are the prefecture’s.
The clearest illustration of what a difficult-to-return zone means on the ground is in the quarterly damage report. National Route 6, the coastal trunk road, is recorded as passable along its whole length, with one qualification: inside the difficult-to-return zone, light vehicles and pedestrians may not pass. A cyclist and a driver meet different rules on the same stretch of tarmac. The same report notes that the Joban Line regained through service on 14 March 2020, when the Tomioka to Namie section reopened.
Two official counts of the remaining evacuees sit three months apart
The English portal page on evacuee numbers, updated 17 August 2026, gives the position as of 1 May 2026: 22,625 people, made up of 18,684 evacuated outside the prefecture, 3,936 within it and 5 whose destination is unknown. Those three components add to 22,625, which matches the printed total; the addition is ours.
The Disaster Response Headquarters report numbered 1805, current as of 08:00 on 14 September 2026, gives the position as of 1 August 2026: 3,899 within the prefecture, 18,469 outside it and 5 unknown, totalling 22,373. The two documents are three months apart, and the difference between the totals is 252 people, a subtraction we performed rather than a figure either source prints. They are consistent rather than contradictory: different reference dates, same series.
| Measure | As of 1 May 2026 | As of 1 August 2026 |
|---|---|---|
| Evacuated outside Fukushima Prefecture | 18,684 | 18,469 |
| Evacuated within Fukushima Prefecture | 3,936 | 3,899 |
| Destination unknown | 5 | 5 |
| Total | 22,625 | 22,373 |
For scale, the prefecture states that in May 2012 approximately 160,000 people were evacuated, around 60,000 outside the prefecture and 100,000 within it. Those are the prefecture’s own rounded figures, and it presents them as approximate.
The prefecture’s damage report puts the death toll at 4,182 and the missing at zero
Report 1805 is the prefecture’s standing tally of damage from the 2011 off the Pacific coast of Tohoku Earthquake, and the index page that carries it says in its own title that it is updated once a quarter. The report is current as of 14 September 2026 and its casualty sheet is headed 1 August 2026; it records 4,182 deaths, no missing persons, 20 seriously injured and 163 slightly injured. The municipal figures it names, before an “and others” note, are Minamisoma City with 1,158 deaths, Soma City with 487, Iwaki City with 468, Namie Town with 628 and Tomioka Town with 480.
The same report, on a sheet also headed 1 August 2026, counts buildings: 15,600 homes destroyed outright, 87,374 half destroyed, 140,055 partially damaged, 1,061 flooded above floor level and 351 below it, plus 1,010 public and 36,895 other non-residential buildings. Forty-three municipalities set up disaster response headquarters. A separate prefectural page on the damage caused by the earthquake and tsunami, updated 17 August 2026, puts the earthquake at magnitude 9.0, “making it the largest earthquake in Japan’s recorded history”, and reaching a maximum seismic intensity of 7 on the JMA scale. Inside Fukushima Prefecture the strongest shaking report 1805 lists for 11 March 2011 is an upper 6 on that scale, at eleven municipalities.
These counts are what the prefecture publishes under the heading of earthquake damage. The report does split the death toll on its detail sheet: of the 4,182 it puts 1,605 down as direct deaths, 2,351 as disaster-related deaths and 226 as people for whom no body was recovered but a death notification was filed. Those three add to 4,182; the addition is ours. The zero for missing persons is defined against that last category, and covers people with neither a body recovered nor a death notification filed.
Fukushima City averages 1.9 degrees in January and 25.5 in August
For weather, the Japan Meteorological Agency’s climate normals for Fukushima station cover 1991 to 2020, thirty years of data in every column, so the figures share a single footing. January’s mean is 1.9 degrees Celsius, with a daily maximum normal of 5.8 and a daily minimum of minus 1.5. August’s mean is 25.5, with a daily maximum of 30.5. The annual mean is 13.4.
| Normal (Fukushima station, 1991 to 2020) | Value |
|---|---|
| Annual mean temperature | 13.4 degrees Celsius |
| January mean / daily maximum / daily minimum | 1.9 / 5.8 / minus 1.5 |
| August mean / daily maximum | 25.5 / 30.5 |
| Annual precipitation | 1,207.0 mm |
| Wettest month | July, 177.7 mm |
| Annual sunshine | 1,753.8 hours |
| Annual snowfall depth, totalled | 122 cm |
| Deepest snow in a year | 26 cm |
| Days with snow in a year | 87.0 |
Two of those lines deserve reading together. The station records 87.0 days with snow a year, yet its deepest snow normal is 26 cm, and its heaviest single day of snowfall totals 21 cm. Snow falls often in Fukushima City and does not often stay deep. January is the snowiest month on both counts, with 49 cm of snowfall totalled and a deepest-snow normal of 20 cm.
One point of vocabulary runs through all of this. Fukushima is a prefecture and also a city inside it, and the prefectural government sits in the city: its published address is 2-16 Sugitsuma-cho, Fukushima City, Fukushima 960-8670. The nuclear power station that carries the prefecture’s name stands on the coast in Okuma and Futaba, roughly the width of the prefecture away from the city whose dose rate is quoted above. A figure for one is not a figure for the other, and the prefecture’s maps are built precisely to show that.
Sources Checked
Fukushima Prefecture (Fukushima Revitalization Information Portal) — Transition and Current Status of Air Dose Rates in Fukushima Prefecture
Confirmed that Figure 1 uses data from 12 to 16 April 2011 and Figure 2 uses FY2025 data collected from 21 April to 16 June 2025, while the explanatory paragraph on the same page instead describes Figure 2 as FY2023 data; that the air dose rate in Fukushima City was 1.91 microsieverts an hour immediately after the earthquake and 0.10 by FY2025, described as approximately 1/19th; that the Aizu region has returned to levels comparable to those before the accident; and that the page was updated on 29 September 2026.
https://www.pref.fukushima.lg.jp/site/portal-english/en-2-3-1.html
Fukushima Prefecture — Radiation levels in the prefecture
Confirmed the comparison table values and dates for Sapporo 0.03, Tokyo 0.04 and Fukuoka 0.06 on 5 March 2019, New York 0.05 on 23 January 2018, Paris 0.04 on 15 October 2017, Beijing 0.07 on 25 January 2018, Seoul 0.12 on 25 January 2018 and Singapore 0.10 on 24 January 2018; that 629 monitoring posts and 2,996 real-time dosimeters are installed; that gathering places are measured once a year and tourist spots twice a year; that a GPS-equipped vehicle and some route buses take measurements; and that the page records its last update as 8 March 2019.
https://www.pref.fukushima.lg.jp/site/portal-english/en02-01.html
Fukushima Prefecture — Transition of the evacuation zones, explanation
Confirmed that only areas classified as difficult-to-return zones remain subject to evacuation orders, and that the page was updated on 1 December 2025.
https://www.pref.fukushima.lg.jp/site/portal-english/en-1-3-1.html
Fukushima Prefecture — Transition of the number of evacuees
Confirmed 22,625 evacuees as of 1 May 2026, comprising 18,684 outside the prefecture, 3,936 within it and 5 of unknown destination, and the figure of approximately 160,000 in May 2012 split as about 60,000 outside and 100,000 within.
https://www.pref.fukushima.lg.jp/site/portal-english/en-1-4-1.html
Fukushima Prefecture — Status of evacuation areas in 12 municipalities
Confirmed the twelve names: Tamura City, Minamisoma City, Kawamata Town, Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village and Iitate Village, on a page updated 31 August 2026.
https://www.pref.fukushima.lg.jp/site/portal-english/en-m5-3.html
Fukushima Prefectural Disaster Response Headquarters — damage report number 1805 on the 2011 off the Pacific coast of Tohoku Earthquake, as of 08:00 on 14 September 2026
Confirmed 4,182 deaths, no missing persons, 20 seriously and 163 slightly injured, with Minamisoma 1,158, Soma 487, Iwaki 468, Namie 628 and Tomioka 480; 15,600 homes destroyed, 87,374 half destroyed, 140,055 partially damaged, 1,061 flooded above and 351 below floor level, 1,010 public and 36,895 other non-residential buildings; 43 municipalities with disaster response headquarters; evacuees as of 1 August 2026 of 3,899 within, 18,469 outside and 5 unknown; National Route 6 passable except to light vehicles and pedestrians inside the difficult-to-return zone; through service on the Joban Line from 14 March 2020; that the casualty and building detail sheets are both headed 1 August 2026; that the death toll is split into 1,605 direct deaths, 2,351 disaster-related deaths and 226 registered on a death notification without a body recovered; and that the strongest shaking listed in the prefecture for 11 March 2011 is an upper 6, at eleven municipalities.
https://www.pref.fukushima.lg.jp/uploaded/life/918180_2719773_misc.pdf
Fukushima Prefecture — Damage caused by the earthquake and tsunami
Confirmed the magnitude of 9.0, the wording “making it the largest earthquake in Japan’s recorded history” and the maximum seismic intensity of 7 on the JMA scale, on a page updated 17 August 2026.
https://www.pref.fukushima.lg.jp/site/portal-english/en-1-1-1.html
Fukushima Prefecture — index page for the damage status reports on the 2011 off the Pacific coast of Tohoku Earthquake
Confirmed that the page title states the reports are updated once a quarter, that report 1805 is the current one, and that the index records its own update as 14 September 2026.
https://www.pref.fukushima.lg.jp/site/portal/shinsai-higaijokyo.html
Japan Meteorological Agency — climate normals for Fukushima (station 47595)
Confirmed that all columns use the 1991 to 2020 period over thirty years, and the values for January mean 1.9, maximum 5.8 and minimum minus 1.5; August mean 25.5 and maximum 30.5; annual mean 13.4; annual precipitation 1,207.0 mm with July at 177.7 mm; annual sunshine 1,753.8 hours; annual snowfall 122 cm with January 49 cm; deepest snow 26 cm in the year and 20 cm in January; greatest daily snowfall 21 cm; and 87.0 days with snow.
https://www.data.jma.go.jp/stats/etrn/view/nml_sfc_ym.php?prec_no=36&block_no=47595
Last updated: October 2026
