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

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 10:00 to 13:00 on Tuesday, October 24,2017 Hachioji
From 13:00 to 16:00 on Tuesday, October 24,2017 Adachi
From 10:00 to 13:00 on Wednesday, October 25,2017 Chofu
From 13:00 to 16:00 on Wednesday, October 25,2017 Ota
From 10:00 to 13:00 on Thursday, October 26,2017 Kodaira
From 13:00 to 16:00 on Thursday, October 26,2017 Edogawa
From 10:00 to 13:00 on Friday, October 27,2017 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 8:00 to 19:00 on Saturday, October 28,2017






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
11:01-12:00, Tue., 17 Oct. 0.0439 0.0369 0.0400
10:01-11:00, Tue., 17 Oct. 0.0438 0.0368 0.0397
09:01-10:00, Tue., 17 Oct. 0.0412 0.0364 0.0384
08:01-09:00, Tue., 17 Oct. 0.0429 0.0363 0.0392
07:01-08:00, Tue., 17 Oct. 0.0452 0.0372 0.0408
06:01-07:00, Tue., 17 Oct. 0.0433 0.0377 0.0409
05:01-06:00, Tue., 17 Oct. 0.0437 0.0354 0.0391
04:01-05:00, Tue., 17 Oct. 0.0442 0.0355 0.0388
03:01-04:00, Tue., 17 Oct. 0.0479 0.0387 0.0434
02:01-03:00, Tue., 17 Oct. 0.0487 0.0406 0.0440
01:01-02:00, Tue., 17 Oct. 0.0439 0.0388 0.0417
00:01-01:00, Tue., 17 Oct. 0.0444 0.0379 0.0406
23:01-24:00, Mon., 16 Oct. 0.0449 0.0365 0.0401
22:01-23:00, Mon., 16 Oct. 0.0452 0.0376 0.0413
21:01-22:00, Mon., 16 Oct. 0.0472 0.0385 0.0426
20:01-21:00, Mon., 16 Oct. 0.0442 0.0391 0.0414
19:01-20:00, Mon., 16 Oct. 0.0475 0.0385 0.0426
18:01-19:00, Mon., 16 Oct. 0.0556 0.0441 0.0502
17:01-18:00, Mon., 16 Oct. 0.0560 0.0468 0.0518
16:01-17:00, Mon., 16 Oct. 0.0565 0.0471 0.0507
15:01-16:00, Mon., 16 Oct. 0.0552 0.0464 0.0508
14:01-15:00, Mon., 16 Oct. 0.0598 0.0488 0.0540
13:01-14:00, Mon., 16 Oct. 0.0600 0.0510 0.0547
12:01-13:00, Mon., 16 Oct. 0.0562 0.0424 0.0487
11:01-12:00, Mon., 16 Oct. 0.0478 0.0396 0.0435
10:01-11:00, Mon., 16 Oct. 0.0468 0.0393 0.0429
09:01-10:00, Mon., 16 Oct. 0.0527 0.0431 0.0474
08:01-09:00, Mon., 16 Oct. 0.0545 0.0415 0.0489
07:01-08:00, Mon., 16 Oct. 0.0491 0.0419 0.0458
06:01-07:00, Mon., 16 Oct. 0.0505 0.0438 0.0473
05:01-06:00, Mon., 16 Oct. 0.0523 0.0454 0.0484
04:01-05:00, Mon., 16 Oct. 0.0522 0.0424 0.0482
03:01-04:00, Mon., 16 Oct. 0.0567 0.0467 0.0507
02:01-03:00, Mon., 16 Oct. 0.0504 0.0405 0.0446
01:01-02:00, Mon., 16 Oct. 0.0469 0.0397 0.0426
00:01-01:00, Mon., 16 Oct. 0.0445 0.0370 0.0413
23:01-24:00, Sun., 15 Oct. 0.0451 0.0389 0.0416
22:01-23:00, Sun., 15 Oct. 0.0436 0.0354 0.0403
21:01-22:00, Sun., 15 Oct. 0.0409 0.0351 0.0375
20:01-21:00, Sun., 15 Oct. 0.0390 0.0342 0.0363
19:01-20:00, Sun., 15 Oct. 0.0420 0.0352 0.0373
18:01-19:00, Sun., 15 Oct. 0.0416 0.0356 0.0377
17:01-18:00, Sun., 15 Oct. 0.0417 0.0361 0.0386
16:01-17:00, Sun., 15 Oct. 0.0427 0.0364 0.0402
15:01-16:00, Sun., 15 Oct. 0.0420 0.0365 0.0397
14:01-15:00, Sun., 15 Oct. 0.0428 0.0362 0.0397
13:01-14:00, Sun., 15 Oct. 0.0460 0.0370 0.0410
12:01-13:00, Sun., 15 Oct. 0.0419 0.0359 0.0387
11:01-12:00, Sun., 15 Oct. 0.0413 0.0352 0.0386
10:01-11:00, Sun., 15 Oct. 0.0408 0.0353 0.0370
09:01-10:00, Sun., 15 Oct. 0.0413 0.0354 0.0377
08:01-09:00, Sun., 15 Oct. 0.0423 0.0361 0.0388
07:01-08:00, Sun., 15 Oct. 0.0430 0.0363 0.0391
06:01-07:00, Sun., 15 Oct. 0.0403 0.0336 0.0370
05:01-06:00, Sun., 15 Oct. 0.0368 0.0336 0.0357
04:01-05:00, Sun., 15 Oct. 0.0372 0.0337 0.0356
03:01-04:00, Sun., 15 Oct. 0.0373 0.0337 0.0356
02:01-03:00, Sun., 15 Oct. 0.0396 0.0334 0.0358
01:01-02:00, Sun., 15 Oct. 0.0370 0.0337 0.0356
00:01-01:00, Sun., 15 Oct. 0.0378 0.0336 0.0356
23:01-24:00, Sat., 14 Oct. 0.0386 0.0341 0.0359
22:01-23:00, Sat., 14 Oct. 0.0373 0.0334 0.0356
21:01-22:00, Sat., 14 Oct. 0.0379 0.0330 0.0360
20:01-21:00, Sat., 14 Oct. 0.0387 0.0346 0.0363
19:01-20:00, Sat., 14 Oct. 0.0390 0.0346 0.0362
18:01-19:00, Sat., 14 Oct. 0.0407 0.0353 0.0370
17:01-18:00, Sat., 14 Oct. 0.0379 0.0344 0.0363
16:01-17:00, Sat., 14 Oct. 0.0395 0.0349 0.0371
15:01-16:00, Sat., 14 Oct. 0.0415 0.0335 0.0364
14:01-15:00, Sat., 14 Oct. 0.0392 0.0322 0.0357
13:01-14:00, Sat., 14 Oct. 0.0385 0.0344 0.0360
12:01-13:00, Sat., 14 Oct. 0.0397 0.0338 0.0361
11:01-12:00, Sat., 14 Oct. 0.0401 0.0345 0.0363
10:01-11:00, Sat., 14 Oct. 0.0417 0.0356 0.0386
09:01-10:00, Sat., 14 Oct. 0.0398 0.0354 0.0369
08:01-09:00, Sat., 14 Oct. 0.0454 0.0374 0.0409
07:01-08:00, Sat., 14 Oct. 0.0454 0.0377 0.0412
06:01-07:00, Sat., 14 Oct. 0.0483 0.0365 0.0412
05:01-06:00, Sat., 14 Oct. 0.0516 0.0420 0.0469
04:01-05:00, Sat., 14 Oct. 0.0515 0.0420 0.0455
03:01-04:00, Sat., 14 Oct. 0.0503 0.0437 0.0465
02:01-03:00, Sat., 14 Oct. 0.0540 0.0447 0.0489
01:01-02:00, Sat., 14 Oct. 0.0546 0.0463 0.0499
00:01-01:00, Sat., 14 Oct. 0.0549 0.0400 0.0496
23:01-24:00, Fri., 13 Oct. 0.0434 0.0346 0.0378
22:01-23:00, Fri., 13 Oct. 0.0390 0.0337 0.0361
21:01-22:00, Fri., 13 Oct. 0.0411 0.0347 0.0370
20:01-21:00, Fri., 13 Oct. 0.0466 0.0358 0.0415
19:01-20:00, Fri., 13 Oct. 0.0525 0.0437 0.0484
18:01-19:00, Fri., 13 Oct. 0.0513 0.0403 0.0457
17:01-18:00, Fri., 13 Oct. 0.0470 0.0392 0.0428
16:01-17:00, Fri., 13 Oct. 0.0460 0.0362 0.0403
15:01-16:00, Fri., 13 Oct. 0.0461 0.0358 0.0408
14:01-15:00, Fri., 13 Oct. 0.0457 0.0373 0.0413
13:01-14:00, Fri., 13 Oct. 0.0474 0.0390 0.0434
12:01-13:00, Fri., 13 Oct. 0.0477 0.0396 0.0435
11:01-12:00, Fri., 13 Oct. 0.0479 0.0408 0.0443
10:01-11:00, Fri., 13 Oct. 0.0489 0.0399 0.0440
09:01-10:00, Fri., 13 Oct. 0.0465 0.0380 0.0429
08:01-09:00, Fri., 13 Oct. 0.0436 0.0365 0.0401
07:01-08:00, Fri., 13 Oct. 0.0419 0.0346 0.0373
06:01-07:00, Fri., 13 Oct. 0.0389 0.0343 0.0357
05:01-06:00, Fri., 13 Oct. 0.0377 0.0334 0.0357
04:01-05:00, Fri., 13 Oct. 0.0385 0.0335 0.0360
03:01-04:00, Fri., 13 Oct. 0.0382 0.0345 0.0360
02:01-03:00, Fri., 13 Oct. 0.0386 0.0336 0.0361
01:01-02:00, Fri., 13 Oct. 0.0389 0.0346 0.0360
00:01-01:00, Fri., 13 Oct. 0.0386 0.0343 0.0360
23:01-24:00, Thu., 12 Oct. 0.0376 0.0339 0.0360
22:01-23:00, Thu., 12 Oct. 0.0384 0.0337 0.0362
21:01-22:00, Thu., 12 Oct. 0.0394 0.0347 0.0365
20:01-21:00, Thu., 12 Oct. 0.0383 0.0347 0.0363
19:01-20:00, Thu., 12 Oct. 0.0398 0.0345 0.0365
18:01-19:00, Thu., 12 Oct. 0.0386 0.0343 0.0363
17:01-18:00, Thu., 12 Oct. 0.0389 0.0347 0.0366
16:01-17:00, Thu., 12 Oct. 0.0379 0.0348 0.0363
15:01-16:00, Thu., 12 Oct. 0.0401 0.0345 0.0364
14:01-15:00, Thu., 12 Oct. 0.0400 0.0353 0.0367
13:01-14:00, Thu., 12 Oct. 0.0399 0.0344 0.0363
12:01-13:00, Thu., 12 Oct. 0.0408 0.0336 0.0364
11:01-12:00, Thu., 12 Oct. 0.0385 0.0343 0.0362
10:01-11:00, Thu., 12 Oct. 0.0403 0.0344 0.0362
09:01-10:00, Thu., 12 Oct. 0.0395 0.0344 0.0365
08:01-09:00, Thu., 12 Oct. 0.0379 0.0338 0.0363
07:01-08:00, Thu., 12 Oct. 0.0394 0.0348 0.0364
06:01-07:00, Thu., 12 Oct. 0.0397 0.0347 0.0363
05:01-06:00, Thu., 12 Oct. 0.0380 0.0336 0.0360
04:01-05:00, Thu., 12 Oct. 0.0395 0.0351 0.0365
03:01-04:00, Thu., 12 Oct. 0.0391 0.0335 0.0364
02:01-03:00, Thu., 12 Oct. 0.0374 0.0342 0.0360
01:01-02:00, Thu., 12 Oct. 0.0411 0.0343 0.0363
00:01-01:00, Thu., 12 Oct. 0.0392 0.0347 0.0363
23:01-24:00, Wed., 11 Oct. 0.0372 0.0340 0.0358
22:01-23:00, Wed., 11 Oct. 0.0383 0.0343 0.0363
21:01-22:00, Wed., 11 Oct. 0.0378 0.0337 0.0359
20:01-21:00, Wed., 11 Oct. 0.0386 0.0340 0.0358
19:01-20:00, Wed., 11 Oct. 0.0384 0.0340 0.0357
18:01-19:00, Wed., 11 Oct. 0.0385 0.0340 0.0361
17:01-18:00, Wed., 11 Oct. 0.0391 0.0340 0.0358
16:01-17:00, Wed., 11 Oct. 0.0378 0.0343 0.0360
15:01-16:00, Wed., 11 Oct. 0.0382 0.0342 0.0361
14:01-15:00, Wed., 11 Oct. 0.0378 0.0342 0.0358
13:01-14:00, Wed., 11 Oct. 0.0371 0.0343 0.0358
12:01-13:00, Wed., 11 Oct. 0.0381 0.0337 0.0360
11:01-12:00, Wed., 11 Oct. 0.0379 0.0339 0.0361
10:01-11:00, Wed., 11 Oct. 0.0378 0.0344 0.0361
09:01-10:00, Wed., 11 Oct. 0.0382 0.0347 0.0365
08:01-09:00, Wed., 11 Oct. 0.0391 0.0340 0.0364
07:01-08:00, Wed., 11 Oct. 0.0411 0.0341 0.0363
06:01-07:00, Wed., 11 Oct. 0.0393 0.0347 0.0363
05:01-06:00, Wed., 11 Oct. 0.0391 0.0347 0.0366
04:01-05:00, Wed., 11 Oct. 0.0384 0.0345 0.0362
03:01-04:00, Wed., 11 Oct. 0.0405 0.0341 0.0362
02:01-03:00, Wed., 11 Oct. 0.0393 0.0344 0.0361
01:01-02:00, Wed., 11 Oct. 0.0377 0.0341 0.0360
00:01-01:00, Wed., 11 Oct. 0.0388 0.0339 0.0361
23:01-24:00, Tue., 10 Oct. 0.0405 0.0337 0.0364
22:01-23:00, Tue., 10 Oct. 0.0376 0.0338 0.0360
21:01-22:00, Tue., 10 Oct. 0.0377 0.0342 0.0360
20:01-21:00, Tue., 10 Oct. 0.0374 0.0321 0.0357
19:01-20:00, Tue., 10 Oct. 0.0392 0.0342 0.0361
18:01-19:00, Tue., 10 Oct. 0.0381 0.0342 0.0359
17:01-18:00, Tue., 10 Oct. 0.0379 0.0344 0.0360
16:01-17:00, Tue., 10 Oct. 0.0376 0.0339 0.0359
15:01-16:00, Tue., 10 Oct. 0.0380 0.0345 0.0358
14:01-15:00, Tue., 10 Oct. 0.0398 0.0342 0.0359
13:01-14:00, Tue., 10 Oct. 0.0384 0.0342 0.0359
12:01-13:00, Tue., 10 Oct. 0.0377 0.0333 0.0357
11:01-12:00, Tue., 10 Oct. 0.0372 0.0338 0.0355
10:01-11:00, Tue., 10 Oct. 0.0377 0.0335 0.0356
09:01-10:00, Tue., 10 Oct. 0.0390 0.0332 0.0360
08:01-09:00, Tue., 10 Oct. 0.0409 0.0343 0.0366
07:01-08:00, Tue., 10 Oct. 0.0392 0.0344 0.0366
06:01-07:00, Tue., 10 Oct. 0.0397 0.0342 0.0365
05:01-06:00, Tue., 10 Oct. 0.0380 0.0338 0.0361
04:01-05:00, Tue., 10 Oct. 0.0377 0.0339 0.0357
03:01-04:00, Tue., 10 Oct. 0.0376 0.0325 0.0355
02:01-03:00, Tue., 10 Oct. 0.0375 0.0333 0.0353
01:01-02:00, Tue., 10 Oct. 0.0384 0.0331 0.0354
00:01-01:00, Tue., 10 Oct. 0.0368 0.0327 0.0352
23:01-24:00, Mon., 09 Oct. 0.0381 0.0325 0.0352
22:01-23:00, Mon., 09 Oct. 0.0383 0.0338 0.0355
21:01-22:00, Mon., 09 Oct. 0.0378 0.0335 0.0354
20:01-21:00, Mon., 09 Oct. 0.0373 0.0332 0.0355
19:01-20:00, Mon., 09 Oct. 0.0375 0.0334 0.0354
18:01-19:00, Mon., 09 Oct. 0.0373 0.0338 0.0357
17:01-18:00, Mon., 09 Oct. 0.0391 0.0328 0.0355
16:01-17:00, Mon., 09 Oct. 0.0375 0.0339 0.0354
15:01-16:00, Mon., 09 Oct. 0.0373 0.0326 0.0354
14:01-15:00, Mon., 09 Oct. 0.0369 0.0322 0.0354
13:01-14:00, Mon., 09 Oct. 0.0373 0.0333 0.0354
12:01-13:00, Mon., 09 Oct. 0.0375 0.0329 0.0353
11:01-12:00, Mon., 09 Oct. 0.0376 0.0336 0.0355
10:01-11:00, Mon., 09 Oct. 0.0383 0.0334 0.0354
09:01-10:00, Mon., 09 Oct. 0.0368 0.0334 0.0353
08:01-09:00, Mon., 09 Oct. 0.0380 0.0331 0.0353
07:01-08:00, Mon., 09 Oct. 0.0376 0.0337 0.0355
06:01-07:00, Mon., 09 Oct. 0.0376 0.0328 0.0350
05:01-06:00, Mon., 09 Oct. 0.0369 0.0331 0.0355
04:01-05:00, Mon., 09 Oct. 0.0374 0.0332 0.0353
03:01-04:00, Mon., 09 Oct. 0.0370 0.0330 0.0353
02:01-03:00, Mon., 09 Oct. 0.0374 0.0335 0.0353
01:01-02:00, Mon., 09 Oct. 0.0385 0.0326 0.0353
00:01-01:00, Mon., 09 Oct. 0.0368 0.0333 0.0352
23:01-24:00, Sun., 08 Oct. 0.0388 0.0330 0.0355
22:01-23:00, Sun., 08 Oct. 0.0373 0.0334 0.0352
21:01-22:00, Sun., 08 Oct. 0.0368 0.0332 0.0351
20:01-21:00, Sun., 08 Oct. 0.0381 0.0332 0.0350
19:01-20:00, Sun., 08 Oct. 0.0368 0.0328 0.0352
18:01-19:00, Sun., 08 Oct. 0.0373 0.0336 0.0353
17:01-18:00, Sun., 08 Oct. 0.0370 0.0325 0.0351
16:01-17:00, Sun., 08 Oct. 0.0370 0.0335 0.0353
15:01-16:00, Sun., 08 Oct. 0.0375 0.0338 0.0352
14:01-15:00, Sun., 08 Oct. 0.0388 0.0334 0.0355
13:01-14:00, Sun., 08 Oct. 0.0388 0.0337 0.0355
12:01-13:00, Sun., 08 Oct. 0.0372 0.0338 0.0354
11:01-12:00, Sun., 08 Oct. 0.0370 0.0342 0.0355
10:01-11:00, Sun., 08 Oct. 0.0384 0.0333 0.0354
09:01-10:00, Sun., 08 Oct. 0.0382 0.0340 0.0357
08:01-09:00, Sun., 08 Oct. 0.0370 0.0335 0.0354
07:01-08:00, Sun., 08 Oct. 0.0372 0.0328 0.0353
06:01-07:00, Sun., 08 Oct. 0.0372 0.0337 0.0350
05:01-06:00, Sun., 08 Oct. 0.0370 0.0325 0.0351
04:01-05:00, Sun., 08 Oct. 0.0372 0.0334 0.0352
03:01-04:00, Sun., 08 Oct. 0.0368 0.0326 0.0349
02:01-03:00, Sun., 08 Oct. 0.0369 0.0336 0.0351
01:01-02:00, Sun., 08 Oct. 0.0368 0.0329 0.0350
00:01-01:00, Sun., 08 Oct. 0.0369 0.0322 0.0349
23:01-24:00, Sat., 07 Oct. 0.0369 0.0323 0.0348
22:01-23:00, Sat., 07 Oct. 0.0385 0.0318 0.0349
21:01-22:00, Sat., 07 Oct. 0.0370 0.0326 0.0347
20:01-21:00, Sat., 07 Oct. 0.0369 0.0329 0.0350
19:01-20:00, Sat., 07 Oct. 0.0372 0.0319 0.0349
18:01-19:00, Sat., 07 Oct. 0.0373 0.0327 0.0351
17:01-18:00, Sat., 07 Oct. 0.0374 0.0328 0.0351
16:01-17:00, Sat., 07 Oct. 0.0366 0.0332 0.0350
15:01-16:00, Sat., 07 Oct. 0.0374 0.0325 0.0350
14:01-15:00, Sat., 07 Oct. 0.0367 0.0329 0.0350
13:01-14:00, Sat., 07 Oct. 0.0387 0.0329 0.0351
12:01-13:00, Sat., 07 Oct. 0.0369 0.0334 0.0353