Radiation doses in the air / Measurement results by the hour (Koto)

We continuously measure radiation doses in the air (air absorbed doses per hour) at monitoring posts. Measurement results can be obtained by the minute, and we gather measurement data and then display them by the hour or by the day.

The maximum value indicates the largest value measured in each time slot (during the hour or during the day), the minimum value the smallest value measured in each time slot, and the average value is the average value for each time slot.

【News about this monitoring post】

We will suspend the provision of data in part or whole of the following time slots by interruption of power supply and relevant facilities due to maintenance and inspection of equipment.

From 9:00 to 13:00 on Tuesday, June 26,2018 Hachioji
From 13:00 to 17:00 on Thursday, June 26,2018 Adachi
From 9:00 to 13:00 on Wednesday, June 27,2018 Chofu
From 13:00 to 17:00 on Wednesday, June 27,2018 Ota
From 9:00 to 13:00 on Thursday, June 28,2018 Kodaira 
From 13:00 to 17:00 on Thursday, June 28,2018 Edogawa
From 9:00 to 13:00 on Friday, June 29,2018 Shinjuku







We will suspend the provision of data in part or whole of the following time slots by interruption of power supply and relevant facilities due to maintenance and inspection of equipment.

From Monday, March 13, 2017 to Tuesday, March 14, 2017

Shown in µGy/h (microgray per hour)

Gray indicates an amount of energy (absorbed dose) when radiation hits a material object, and 1 gray (Gy) of radiation doses in the air can be converted to 1 sievert (Sv).

Measurement time Dose rate
μGy/h (microgray per hour)
Maximum value Minimum value Average value
08:01-09:00, Sat., 23 Jun. 0.0369 0.0330 0.0353
07:01-08:00, Sat., 23 Jun. 0.0375 0.0335 0.0356
06:01-07:00, Sat., 23 Jun. 0.0371 0.0338 0.0355
05:01-06:00, Sat., 23 Jun. 0.0383 0.0333 0.0353
04:01-05:00, Sat., 23 Jun. 0.0382 0.0332 0.0353
03:01-04:00, Sat., 23 Jun. 0.0380 0.0326 0.0351
02:01-03:00, Sat., 23 Jun. 0.0373 0.0332 0.0354
01:01-02:00, Sat., 23 Jun. 0.0376 0.0330 0.0354
00:01-01:00, Sat., 23 Jun. 0.0374 0.0333 0.0352
23:01-24:00, Fri., 22 Jun. 0.0375 0.0328 0.0351
22:01-23:00, Fri., 22 Jun. 0.0373 0.0325 0.0352
21:01-22:00, Fri., 22 Jun. 0.0379 0.0330 0.0350
20:01-21:00, Fri., 22 Jun. 0.0372 0.0332 0.0351
19:01-20:00, Fri., 22 Jun. 0.0373 0.0332 0.0350
18:01-19:00, Fri., 22 Jun. 0.0370 0.0332 0.0349
17:01-18:00, Fri., 22 Jun. 0.0373 0.0329 0.0350
16:01-17:00, Fri., 22 Jun. 0.0374 0.0322 0.0349
15:01-16:00, Fri., 22 Jun. 0.0369 0.0331 0.0351
14:01-15:00, Fri., 22 Jun. 0.0371 0.0332 0.0351
13:01-14:00, Fri., 22 Jun. 0.0375 0.0328 0.0350
12:01-13:00, Fri., 22 Jun. 0.0365 0.0321 0.0347
11:01-12:00, Fri., 22 Jun. 0.0367 0.0325 0.0349
10:01-11:00, Fri., 22 Jun. 0.0374 0.0328 0.0349
09:01-10:00, Fri., 22 Jun. 0.0378 0.0327 0.0351
08:01-09:00, Fri., 22 Jun. 0.0378 0.0331 0.0353
07:01-08:00, Fri., 22 Jun. 0.0381 0.0331 0.0355
06:01-07:00, Fri., 22 Jun. 0.0372 0.0333 0.0351
05:01-06:00, Fri., 22 Jun. 0.0383 0.0333 0.0353
04:01-05:00, Fri., 22 Jun. 0.0388 0.0328 0.0353
03:01-04:00, Fri., 22 Jun. 0.0381 0.0322 0.0352
02:01-03:00, Fri., 22 Jun. 0.0371 0.0330 0.0352
01:01-02:00, Fri., 22 Jun. 0.0371 0.0330 0.0350
00:01-01:00, Fri., 22 Jun. 0.0369 0.0330 0.0350
23:01-24:00, Thu., 21 Jun. 0.0372 0.0331 0.0350
22:01-23:00, Thu., 21 Jun. 0.0377 0.0327 0.0351
21:01-22:00, Thu., 21 Jun. 0.0367 0.0325 0.0346
20:01-21:00, Thu., 21 Jun. 0.0378 0.0334 0.0354
19:01-20:00, Thu., 21 Jun. 0.0369 0.0330 0.0348
18:01-19:00, Thu., 21 Jun. 0.0369 0.0327 0.0351
17:01-18:00, Thu., 21 Jun. 0.0368 0.0325 0.0350
16:01-17:00, Thu., 21 Jun. 0.0367 0.0330 0.0350
15:01-16:00, Thu., 21 Jun. 0.0369 0.0322 0.0349
14:01-15:00, Thu., 21 Jun. 0.0370 0.0321 0.0348
13:01-14:00, Thu., 21 Jun. 0.0369 0.0328 0.0347
12:01-13:00, Thu., 21 Jun. 0.0376 0.0330 0.0348
11:01-12:00, Thu., 21 Jun. 0.0380 0.0330 0.0349
10:01-11:00, Thu., 21 Jun. 0.0372 0.0328 0.0350
09:01-10:00, Thu., 21 Jun. 0.0378 0.0324 0.0347
08:01-09:00, Thu., 21 Jun. 0.0367 0.0326 0.0348
07:01-08:00, Thu., 21 Jun. 0.0365 0.0332 0.0348
06:01-07:00, Thu., 21 Jun. 0.0376 0.0324 0.0355
05:01-06:00, Thu., 21 Jun. 0.0405 0.0341 0.0372
04:01-05:00, Thu., 21 Jun. 0.0437 0.0381 0.0411
03:01-04:00, Thu., 21 Jun. 0.0432 0.0365 0.0398
02:01-03:00, Thu., 21 Jun. 0.0412 0.0338 0.0374
01:01-02:00, Thu., 21 Jun. 0.0378 0.0332 0.0353
00:01-01:00, Thu., 21 Jun. 0.0389 0.0331 0.0364
23:01-24:00, Wed., 20 Jun. 0.0420 0.0361 0.0392
22:01-23:00, Wed., 20 Jun. 0.0423 0.0371 0.0396
21:01-22:00, Wed., 20 Jun. 0.0398 0.0362 0.0380
20:01-21:00, Wed., 20 Jun. 0.0383 0.0343 0.0366
19:01-20:00, Wed., 20 Jun. 0.0379 0.0342 0.0358
18:01-19:00, Wed., 20 Jun. 0.0376 0.0332 0.0355
17:01-18:00, Wed., 20 Jun. 0.0375 0.0329 0.0348
16:01-17:00, Wed., 20 Jun. 0.0364 0.0328 0.0347
15:01-16:00, Wed., 20 Jun. 0.0368 0.0327 0.0349
14:01-15:00, Wed., 20 Jun. 0.0369 0.0320 0.0347
13:01-14:00, Wed., 20 Jun. 0.0370 0.0336 0.0353
12:01-13:00, Wed., 20 Jun. 0.0397 0.0342 0.0365
11:01-12:00, Wed., 20 Jun. 0.0408 0.0351 0.0379
10:01-11:00, Wed., 20 Jun. 0.0389 0.0348 0.0369
09:01-10:00, Wed., 20 Jun. 0.0390 0.0338 0.0368
08:01-09:00, Wed., 20 Jun. 0.0390 0.0350 0.0369
07:01-08:00, Wed., 20 Jun. 0.0405 0.0360 0.0382
06:01-07:00, Wed., 20 Jun. 0.0402 0.0344 0.0369
05:01-06:00, Wed., 20 Jun. 0.0390 0.0349 0.0372
04:01-05:00, Wed., 20 Jun. 0.0385 0.0338 0.0360
03:01-04:00, Wed., 20 Jun. 0.0375 0.0331 0.0354
02:01-03:00, Wed., 20 Jun. 0.0373 0.0328 0.0349
01:01-02:00, Wed., 20 Jun. 0.0383 0.0326 0.0350
00:01-01:00, Wed., 20 Jun. 0.0372 0.0330 0.0348
23:01-24:00, Tue., 19 Jun. 0.0370 0.0331 0.0349
22:01-23:00, Tue., 19 Jun. 0.0376 0.0329 0.0348
21:01-22:00, Tue., 19 Jun. 0.0375 0.0323 0.0347
20:01-21:00, Tue., 19 Jun. 0.0363 0.0326 0.0346
19:01-20:00, Tue., 19 Jun. 0.0376 0.0332 0.0347
18:01-19:00, Tue., 19 Jun. 0.0375 0.0325 0.0347
17:01-18:00, Tue., 19 Jun. 0.0369 0.0333 0.0348
16:01-17:00, Tue., 19 Jun. 0.0369 0.0327 0.0347
15:01-16:00, Tue., 19 Jun. 0.0369 0.0325 0.0346
14:01-15:00, Tue., 19 Jun. 0.0373 0.0333 0.0348
13:01-14:00, Tue., 19 Jun. 0.0370 0.0327 0.0347
12:01-13:00, Tue., 19 Jun. 0.0366 0.0328 0.0345
11:01-12:00, Tue., 19 Jun. 0.0377 0.0324 0.0350
10:01-11:00, Tue., 19 Jun. 0.0368 0.0330 0.0349
09:01-10:00, Tue., 19 Jun. 0.0372 0.0330 0.0349
08:01-09:00, Tue., 19 Jun. 0.0369 0.0333 0.0350
07:01-08:00, Tue., 19 Jun. 0.0373 0.0332 0.0351
06:01-07:00, Tue., 19 Jun. 0.0369 0.0324 0.0348
05:01-06:00, Tue., 19 Jun. 0.0376 0.0326 0.0350
04:01-05:00, Tue., 19 Jun. 0.0375 0.0334 0.0352
03:01-04:00, Tue., 19 Jun. 0.0378 0.0329 0.0350
02:01-03:00, Tue., 19 Jun. 0.0372 0.0328 0.0350
01:01-02:00, Tue., 19 Jun. 0.0378 0.0330 0.0350
00:01-01:00, Tue., 19 Jun. 0.0373 0.0331 0.0349
23:01-24:00, Mon., 18 Jun. 0.0375 0.0333 0.0352
22:01-23:00, Mon., 18 Jun. 0.0378 0.0335 0.0353
21:01-22:00, Mon., 18 Jun. 0.0385 0.0326 0.0354
20:01-21:00, Mon., 18 Jun. 0.0387 0.0338 0.0356
19:01-20:00, Mon., 18 Jun. 0.0380 0.0340 0.0360
18:01-19:00, Mon., 18 Jun. 0.0372 0.0330 0.0352
17:01-18:00, Mon., 18 Jun. 0.0377 0.0329 0.0348
16:01-17:00, Mon., 18 Jun. 0.0378 0.0326 0.0351
15:01-16:00, Mon., 18 Jun. 0.0375 0.0327 0.0353
14:01-15:00, Mon., 18 Jun. 0.0376 0.0333 0.0353
13:01-14:00, Mon., 18 Jun. 0.0383 0.0331 0.0351
12:01-13:00, Mon., 18 Jun. 0.0375 0.0327 0.0351
11:01-12:00, Mon., 18 Jun. 0.0371 0.0328 0.0351
10:01-11:00, Mon., 18 Jun. 0.0374 0.0326 0.0352
09:01-10:00, Mon., 18 Jun. 0.0365 0.0332 0.0350
08:01-09:00, Mon., 18 Jun. 0.0372 0.0329 0.0350
07:01-08:00, Mon., 18 Jun. 0.0381 0.0340 0.0356
06:01-07:00, Mon., 18 Jun. 0.0375 0.0339 0.0355
05:01-06:00, Mon., 18 Jun. 0.0371 0.0324 0.0353
04:01-05:00, Mon., 18 Jun. 0.0373 0.0334 0.0352
03:01-04:00, Mon., 18 Jun. 0.0369 0.0334 0.0352
02:01-03:00, Mon., 18 Jun. 0.0387 0.0334 0.0355
01:01-02:00, Mon., 18 Jun. 0.0365 0.0325 0.0349
00:01-01:00, Mon., 18 Jun. 0.0370 0.0330 0.0350
23:01-24:00, Sun., 17 Jun. 0.0377 0.0332 0.0350
22:01-23:00, Sun., 17 Jun. 0.0376 0.0326 0.0349
21:01-22:00, Sun., 17 Jun. 0.0375 0.0323 0.0350
20:01-21:00, Sun., 17 Jun. 0.0368 0.0326 0.0349
19:01-20:00, Sun., 17 Jun. 0.0374 0.0330 0.0350
18:01-19:00, Sun., 17 Jun. 0.0369 0.0330 0.0351
17:01-18:00, Sun., 17 Jun. 0.0373 0.0322 0.0351
16:01-17:00, Sun., 17 Jun. 0.0374 0.0333 0.0352
15:01-16:00, Sun., 17 Jun. 0.0372 0.0326 0.0349
14:01-15:00, Sun., 17 Jun. 0.0379 0.0331 0.0350
13:01-14:00, Sun., 17 Jun. 0.0368 0.0334 0.0349
12:01-13:00, Sun., 17 Jun. 0.0375 0.0328 0.0351
11:01-12:00, Sun., 17 Jun. 0.0377 0.0331 0.0349
10:01-11:00, Sun., 17 Jun. 0.0372 0.0331 0.0350
09:01-10:00, Sun., 17 Jun. 0.0371 0.0333 0.0351
08:01-09:00, Sun., 17 Jun. 0.0374 0.0332 0.0350
07:01-08:00, Sun., 17 Jun. 0.0371 0.0331 0.0349
06:01-07:00, Sun., 17 Jun. 0.0373 0.0326 0.0349
05:01-06:00, Sun., 17 Jun. 0.0369 0.0328 0.0348
04:01-05:00, Sun., 17 Jun. 0.0376 0.0329 0.0351
03:01-04:00, Sun., 17 Jun. 0.0378 0.0329 0.0351
02:01-03:00, Sun., 17 Jun. 0.0368 0.0334 0.0349
01:01-02:00, Sun., 17 Jun. 0.0369 0.0325 0.0349
00:01-01:00, Sun., 17 Jun. 0.0375 0.0326 0.0350
23:01-24:00, Sat., 16 Jun. 0.0371 0.0331 0.0350
22:01-23:00, Sat., 16 Jun. 0.0369 0.0327 0.0350
21:01-22:00, Sat., 16 Jun. 0.0367 0.0328 0.0349
20:01-21:00, Sat., 16 Jun. 0.0368 0.0330 0.0351
19:01-20:00, Sat., 16 Jun. 0.0367 0.0326 0.0349
18:01-19:00, Sat., 16 Jun. 0.0364 0.0329 0.0350
17:01-18:00, Sat., 16 Jun. 0.0367 0.0328 0.0349
16:01-17:00, Sat., 16 Jun. 0.0367 0.0328 0.0348
15:01-16:00, Sat., 16 Jun. 0.0370 0.0333 0.0350
14:01-15:00, Sat., 16 Jun. 0.0368 0.0326 0.0349
13:01-14:00, Sat., 16 Jun. 0.0381 0.0318 0.0350
12:01-13:00, Sat., 16 Jun. 0.0371 0.0328 0.0348
11:01-12:00, Sat., 16 Jun. 0.0375 0.0327 0.0350
10:01-11:00, Sat., 16 Jun. 0.0365 0.0332 0.0348
09:01-10:00, Sat., 16 Jun. 0.0379 0.0329 0.0351
08:01-09:00, Sat., 16 Jun. 0.0371 0.0328 0.0350
07:01-08:00, Sat., 16 Jun. 0.0380 0.0330 0.0353
06:01-07:00, Sat., 16 Jun. 0.0380 0.0336 0.0356
05:01-06:00, Sat., 16 Jun. 0.0384 0.0341 0.0364
04:01-05:00, Sat., 16 Jun. 0.0393 0.0345 0.0370
03:01-04:00, Sat., 16 Jun. 0.0392 0.0337 0.0364
02:01-03:00, Sat., 16 Jun. 0.0372 0.0333 0.0352
01:01-02:00, Sat., 16 Jun. 0.0378 0.0326 0.0350
00:01-01:00, Sat., 16 Jun. 0.0378 0.0331 0.0351
23:01-24:00, Fri., 15 Jun. 0.0374 0.0332 0.0351
22:01-23:00, Fri., 15 Jun. 0.0375 0.0327 0.0348
21:01-22:00, Fri., 15 Jun. 0.0371 0.0326 0.0349
20:01-21:00, Fri., 15 Jun. 0.0369 0.0325 0.0349
19:01-20:00, Fri., 15 Jun. 0.0367 0.0335 0.0349
18:01-19:00, Fri., 15 Jun. 0.0368 0.0331 0.0351
17:01-18:00, Fri., 15 Jun. 0.0376 0.0332 0.0351
16:01-17:00, Fri., 15 Jun. 0.0377 0.0337 0.0353
15:01-16:00, Fri., 15 Jun. 0.0381 0.0340 0.0359
14:01-15:00, Fri., 15 Jun. 0.0397 0.0345 0.0366
13:01-14:00, Fri., 15 Jun. 0.0381 0.0343 0.0361
12:01-13:00, Fri., 15 Jun. 0.0385 0.0346 0.0368
11:01-12:00, Fri., 15 Jun. 0.0397 0.0350 0.0369
10:01-11:00, Fri., 15 Jun. 0.0385 0.0346 0.0366
09:01-10:00, Fri., 15 Jun. 0.0376 0.0330 0.0354
08:01-09:00, Fri., 15 Jun. 0.0378 0.0329 0.0352
07:01-08:00, Fri., 15 Jun. 0.0376 0.0332 0.0352
06:01-07:00, Fri., 15 Jun. 0.0371 0.0326 0.0350
05:01-06:00, Fri., 15 Jun. 0.0371 0.0325 0.0351
04:01-05:00, Fri., 15 Jun. 0.0378 0.0330 0.0351
03:01-04:00, Fri., 15 Jun. 0.0376 0.0337 0.0354
02:01-03:00, Fri., 15 Jun. 0.0373 0.0335 0.0351
01:01-02:00, Fri., 15 Jun. 0.0382 0.0333 0.0350
00:01-01:00, Fri., 15 Jun. 0.0369 0.0333 0.0349
23:01-24:00, Thu., 14 Jun. 0.0374 0.0332 0.0351
22:01-23:00, Thu., 14 Jun. 0.0373 0.0326 0.0350
21:01-22:00, Thu., 14 Jun. 0.0375 0.0328 0.0350
20:01-21:00, Thu., 14 Jun. 0.0372 0.0327 0.0347
19:01-20:00, Thu., 14 Jun. 0.0374 0.0312 0.0348
18:01-19:00, Thu., 14 Jun. 0.0369 0.0326 0.0346
17:01-18:00, Thu., 14 Jun. 0.0373 0.0330 0.0348
16:01-17:00, Thu., 14 Jun. 0.0382 0.0325 0.0348
15:01-16:00, Thu., 14 Jun. 0.0373 0.0326 0.0350
14:01-15:00, Thu., 14 Jun. 0.0376 0.0334 0.0350
13:01-14:00, Thu., 14 Jun. 0.0371 0.0332 0.0348
12:01-13:00, Thu., 14 Jun. 0.0376 0.0323 0.0350
11:01-12:00, Thu., 14 Jun. 0.0373 0.0324 0.0347
10:01-11:00, Thu., 14 Jun. 0.0370 0.0327 0.0350
09:01-10:00, Thu., 14 Jun. 0.0370 0.0330 0.0350
08:01-09:00, Thu., 14 Jun. 0.0380 0.0331 0.0352
07:01-08:00, Thu., 14 Jun. 0.0374 0.0331 0.0351
06:01-07:00, Thu., 14 Jun. 0.0373 0.0329 0.0351
05:01-06:00, Thu., 14 Jun. 0.0369 0.0329 0.0351
04:01-05:00, Thu., 14 Jun. 0.0368 0.0324 0.0349
03:01-04:00, Thu., 14 Jun. 0.0374 0.0334 0.0352
02:01-03:00, Thu., 14 Jun. 0.0376 0.0334 0.0352
01:01-02:00, Thu., 14 Jun. 0.0368 0.0330 0.0351
00:01-01:00, Thu., 14 Jun. 0.0369 0.0331 0.0352
23:01-24:00, Wed., 13 Jun. 0.0369 0.0333 0.0353
22:01-23:00, Wed., 13 Jun. 0.0369 0.0332 0.0351
21:01-22:00, Wed., 13 Jun. 0.0375 0.0334 0.0350
20:01-21:00, Wed., 13 Jun. 0.0367 0.0329 0.0349
19:01-20:00, Wed., 13 Jun. 0.0364 0.0330 0.0347
18:01-19:00, Wed., 13 Jun. 0.0374 0.0330 0.0351
17:01-18:00, Wed., 13 Jun. 0.0371 0.0333 0.0350
16:01-17:00, Wed., 13 Jun. 0.0368 0.0330 0.0348
15:01-16:00, Wed., 13 Jun. 0.0371 0.0321 0.0350
14:01-15:00, Wed., 13 Jun. 0.0374 0.0335 0.0354
13:01-14:00, Wed., 13 Jun. 0.0373 0.0326 0.0351
12:01-13:00, Wed., 13 Jun. 0.0371 0.0327 0.0350
11:01-12:00, Wed., 13 Jun. 0.0372 0.0329 0.0349
10:01-11:00, Wed., 13 Jun. 0.0372 0.0327 0.0348
09:01-10:00, Wed., 13 Jun. 0.0371 0.0334 0.0350