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

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 update the monitoring post from Wednesday, March 8 to Thursday, March 9, 2023. Since it is not possible to measure the radiation dose in the atmosphere during the update work, the provision of measurement results will be temporarily suspended at the following monitoring posts.

Adachi Bureau (Toneri Park) Wednesday, March 8, from around 8 a.m. to 6 p.m.
Chofu Bureau (Chofu Airfield) Thursday, March 9, from 8 a.m. to 6 p.m.


On Friday, March 10, 2023, from around 9 a.m. to around noon, maintenance and inspection of the Kodaira Bureau (Medicinal Botanical Garden) will be conducted.
Since the amount of radiation in the atmosphere cannot be measured during maintenance and inspection, the provision of measurement results is temporarily suspended.

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
16:01-17:00, Fri., 02 Jun. 0.0405 0.0354 0.0375
15:01-16:00, Fri., 02 Jun. 0.0402 0.0353 0.0372
14:01-15:00, Fri., 02 Jun. 0.0407 0.0349 0.0374
13:01-14:00, Fri., 02 Jun. 0.0445 0.0362 0.0381
12:01-13:00, Fri., 02 Jun. 0.0410 0.0349 0.0371
11:01-12:00, Fri., 02 Jun. 0.0414 0.0361 0.0377
10:01-11:00, Fri., 02 Jun. 0.0431 0.0360 0.0395
09:01-10:00, Fri., 02 Jun. 0.0443 0.0374 0.0405
08:01-09:00, Fri., 02 Jun. 0.0449 0.0397 0.0421
07:01-08:00, Fri., 02 Jun. 0.0480 0.0404 0.0431
06:01-07:00, Fri., 02 Jun. 0.0496 0.0400 0.0435
05:01-06:00, Fri., 02 Jun. 0.0491 0.0398 0.0436
04:01-05:00, Fri., 02 Jun. 0.0496 0.0427 0.0465
03:01-04:00, Fri., 02 Jun. 0.0510 0.0422 0.0472
02:01-03:00, Fri., 02 Jun. 0.0489 0.0408 0.0450
01:01-02:00, Fri., 02 Jun. 0.0457 0.0376 0.0423
00:01-01:00, Fri., 02 Jun. 0.0425 0.0356 0.0385
23:01-24:00, Thu., 01 Jun. 0.0378 0.0341 0.0362
22:01-23:00, Thu., 01 Jun. 0.0388 0.0329 0.0359
21:01-22:00, Thu., 01 Jun. 0.0380 0.0334 0.0360
20:01-21:00, Thu., 01 Jun. 0.0382 0.0328 0.0357
19:01-20:00, Thu., 01 Jun. 0.0407 0.0329 0.0359
18:01-19:00, Thu., 01 Jun. 0.0373 0.0336 0.0357
17:01-18:00, Thu., 01 Jun. 0.0386 0.0335 0.0355
16:01-17:00, Thu., 01 Jun. 0.0394 0.0342 0.0358
15:01-16:00, Thu., 01 Jun. 0.0383 0.0342 0.0358
14:01-15:00, Thu., 01 Jun. 0.0385 0.0333 0.0356
13:01-14:00, Thu., 01 Jun. 0.0398 0.0334 0.0353
12:01-13:00, Thu., 01 Jun. 0.0375 0.0335 0.0354
11:01-12:00, Thu., 01 Jun. 0.0370 0.0337 0.0355
10:01-11:00, Thu., 01 Jun. 0.0373 0.0337 0.0355
09:01-10:00, Thu., 01 Jun. 0.0372 0.0330 0.0356
08:01-09:00, Thu., 01 Jun. 0.0396 0.0333 0.0359
07:01-08:00, Thu., 01 Jun. 0.0405 0.0347 0.0368
06:01-07:00, Thu., 01 Jun. 0.0400 0.0346 0.0367
05:01-06:00, Thu., 01 Jun. 0.0405 0.0346 0.0366
04:01-05:00, Thu., 01 Jun. 0.0395 0.0341 0.0365
03:01-04:00, Thu., 01 Jun. 0.0405 0.0349 0.0367
02:01-03:00, Thu., 01 Jun. 0.0401 0.0340 0.0363
01:01-02:00, Thu., 01 Jun. 0.0380 0.0338 0.0357
00:01-01:00, Thu., 01 Jun. 0.0369 0.0333 0.0356
23:01-24:00, Wed., 31 May. 0.0390 0.0332 0.0357
22:01-23:00, Wed., 31 May. 0.0376 0.0335 0.0357
21:01-22:00, Wed., 31 May. 0.0389 0.0334 0.0359
20:01-21:00, Wed., 31 May. 0.0376 0.0331 0.0357
19:01-20:00, Wed., 31 May. 0.0391 0.0336 0.0357
18:01-19:00, Wed., 31 May. 0.0386 0.0330 0.0357
17:01-18:00, Wed., 31 May. 0.0381 0.0337 0.0356
16:01-17:00, Wed., 31 May. 0.0374 0.0334 0.0357
15:01-16:00, Wed., 31 May. 0.0383 0.0331 0.0357
14:01-15:00, Wed., 31 May. 0.0380 0.0336 0.0356
13:01-14:00, Wed., 31 May. 0.0377 0.0333 0.0355
12:01-13:00, Wed., 31 May. 0.0388 0.0339 0.0356
11:01-12:00, Wed., 31 May. 0.0390 0.0337 0.0357
10:01-11:00, Wed., 31 May. 0.0385 0.0337 0.0357
09:01-10:00, Wed., 31 May. 0.0372 0.0337 0.0357
08:01-09:00, Wed., 31 May. 0.0387 0.0335 0.0360
07:01-08:00, Wed., 31 May. 0.0393 0.0343 0.0365
06:01-07:00, Wed., 31 May. 0.0391 0.0346 0.0362
05:01-06:00, Wed., 31 May. 0.0430 0.0353 0.0380
04:01-05:00, Wed., 31 May. 0.0464 0.0372 0.0423
03:01-04:00, Wed., 31 May. 0.0650 0.0433 0.0535
02:01-03:00, Wed., 31 May. 0.0694 0.0574 0.0642
01:01-02:00, Wed., 31 May. 0.0594 0.0341 0.0424
00:01-01:00, Wed., 31 May. 0.0379 0.0338 0.0360
23:01-24:00, Tue., 30 May. 0.0402 0.0340 0.0361
22:01-23:00, Tue., 30 May. 0.0391 0.0337 0.0359
21:01-22:00, Tue., 30 May. 0.0400 0.0335 0.0361
20:01-21:00, Tue., 30 May. 0.0403 0.0344 0.0362
19:01-20:00, Tue., 30 May. 0.0381 0.0334 0.0357
18:01-19:00, Tue., 30 May. 0.0404 0.0331 0.0359
17:01-18:00, Tue., 30 May. 0.0377 0.0335 0.0356
16:01-17:00, Tue., 30 May. 0.0376 0.0339 0.0358
15:01-16:00, Tue., 30 May. 0.0398 0.0337 0.0359
14:01-15:00, Tue., 30 May. 0.0378 0.0338 0.0359
13:01-14:00, Tue., 30 May. 0.0390 0.0340 0.0358
12:01-13:00, Tue., 30 May. 0.0391 0.0325 0.0360
11:01-12:00, Tue., 30 May. 0.0395 0.0337 0.0360
10:01-11:00, Tue., 30 May. 0.0386 0.0340 0.0362
09:01-10:00, Tue., 30 May. 0.0393 0.0347 0.0369
08:01-09:00, Tue., 30 May. 0.0418 0.0346 0.0375
07:01-08:00, Tue., 30 May. 0.0424 0.0341 0.0380
06:01-07:00, Tue., 30 May. 0.0426 0.0344 0.0373
05:01-06:00, Tue., 30 May. 0.0403 0.0343 0.0372
04:01-05:00, Tue., 30 May. 0.0405 0.0350 0.0373
03:01-04:00, Tue., 30 May. 0.0414 0.0352 0.0371
02:01-03:00, Tue., 30 May. 0.0417 0.0354 0.0380
01:01-02:00, Tue., 30 May. 0.0393 0.0352 0.0370
00:01-01:00, Tue., 30 May. 0.0439 0.0355 0.0389
23:01-24:00, Mon., 29 May. 0.0461 0.0379 0.0422
22:01-23:00, Mon., 29 May. 0.0502 0.0428 0.0462
21:01-22:00, Mon., 29 May. 0.0532 0.0444 0.0488
20:01-21:00, Mon., 29 May. 0.0566 0.0478 0.0517
19:01-20:00, Mon., 29 May. 0.0514 0.0381 0.0438
18:01-19:00, Mon., 29 May. 0.0429 0.0359 0.0385
17:01-18:00, Mon., 29 May. 0.0474 0.0387 0.0421
16:01-17:00, Mon., 29 May. 0.0472 0.0407 0.0435
15:01-16:00, Mon., 29 May. 0.0454 0.0369 0.0413
14:01-15:00, Mon., 29 May. 0.0436 0.0358 0.0387
13:01-14:00, Mon., 29 May. 0.0387 0.0336 0.0361
12:01-13:00, Mon., 29 May. 0.0378 0.0333 0.0357
11:01-12:00, Mon., 29 May. 0.0416 0.0352 0.0373
10:01-11:00, Mon., 29 May. 0.0458 0.0368 0.0415
09:01-10:00, Mon., 29 May. 0.0445 0.0366 0.0410
08:01-09:00, Mon., 29 May. 0.0442 0.0366 0.0403
07:01-08:00, Mon., 29 May. 0.0441 0.0377 0.0411
06:01-07:00, Mon., 29 May. 0.0479 0.0386 0.0429
05:01-06:00, Mon., 29 May. 0.0483 0.0424 0.0455
04:01-05:00, Mon., 29 May. 0.0472 0.0405 0.0440
03:01-04:00, Mon., 29 May. 0.0449 0.0367 0.0409
02:01-03:00, Mon., 29 May. 0.0432 0.0355 0.0393
01:01-02:00, Mon., 29 May. 0.0420 0.0351 0.0376
00:01-01:00, Mon., 29 May. 0.0397 0.0354 0.0372
23:01-24:00, Sun., 28 May. 0.0411 0.0352 0.0374
22:01-23:00, Sun., 28 May. 0.0434 0.0359 0.0395
21:01-22:00, Sun., 28 May. 0.0456 0.0344 0.0384
20:01-21:00, Sun., 28 May. 0.0398 0.0342 0.0366
19:01-20:00, Sun., 28 May. 0.0405 0.0334 0.0357
18:01-19:00, Sun., 28 May. 0.0373 0.0337 0.0355
17:01-18:00, Sun., 28 May. 0.0382 0.0331 0.0354
16:01-17:00, Sun., 28 May. 0.0373 0.0335 0.0353
15:01-16:00, Sun., 28 May. 0.0398 0.0336 0.0356
14:01-15:00, Sun., 28 May. 0.0381 0.0337 0.0356
13:01-14:00, Sun., 28 May. 0.0378 0.0335 0.0357
12:01-13:00, Sun., 28 May. 0.0383 0.0335 0.0357
11:01-12:00, Sun., 28 May. 0.0375 0.0334 0.0357
10:01-11:00, Sun., 28 May. 0.0380 0.0344 0.0358
09:01-10:00, Sun., 28 May. 0.0384 0.0337 0.0357
08:01-09:00, Sun., 28 May. 0.0397 0.0338 0.0358
07:01-08:00, Sun., 28 May. 0.0392 0.0334 0.0360
06:01-07:00, Sun., 28 May. 0.0379 0.0332 0.0359
05:01-06:00, Sun., 28 May. 0.0382 0.0342 0.0357
04:01-05:00, Sun., 28 May. 0.0384 0.0333 0.0360
03:01-04:00, Sun., 28 May. 0.0373 0.0342 0.0358
02:01-03:00, Sun., 28 May. 0.0380 0.0337 0.0357
01:01-02:00, Sun., 28 May. 0.0387 0.0337 0.0356
00:01-01:00, Sun., 28 May. 0.0390 0.0335 0.0356
23:01-24:00, Sat., 27 May. 0.0376 0.0337 0.0356
22:01-23:00, Sat., 27 May. 0.0382 0.0337 0.0357
21:01-22:00, Sat., 27 May. 0.0390 0.0337 0.0358
20:01-21:00, Sat., 27 May. 0.0388 0.0340 0.0358
19:01-20:00, Sat., 27 May. 0.0384 0.0336 0.0357
18:01-19:00, Sat., 27 May. 0.0375 0.0345 0.0358
17:01-18:00, Sat., 27 May. 0.0386 0.0332 0.0359
16:01-17:00, Sat., 27 May. 0.0389 0.0336 0.0357
15:01-16:00, Sat., 27 May. 0.0373 0.0336 0.0356
14:01-15:00, Sat., 27 May. 0.0371 0.0333 0.0358
13:01-14:00, Sat., 27 May. 0.0377 0.0327 0.0358
12:01-13:00, Sat., 27 May. 0.0381 0.0337 0.0355
11:01-12:00, Sat., 27 May. 0.0387 0.0339 0.0360
10:01-11:00, Sat., 27 May. 0.0380 0.0335 0.0358
09:01-10:00, Sat., 27 May. 0.0375 0.0332 0.0359
08:01-09:00, Sat., 27 May. 0.0396 0.0343 0.0361
07:01-08:00, Sat., 27 May. 0.0390 0.0341 0.0363
06:01-07:00, Sat., 27 May. 0.0378 0.0341 0.0359
05:01-06:00, Sat., 27 May. 0.0392 0.0332 0.0361
04:01-05:00, Sat., 27 May. 0.0391 0.0341 0.0358
03:01-04:00, Sat., 27 May. 0.0393 0.0341 0.0358
02:01-03:00, Sat., 27 May. 0.0387 0.0337 0.0357
01:01-02:00, Sat., 27 May. 0.0386 0.0340 0.0357
00:01-01:00, Sat., 27 May. 0.0394 0.0323 0.0357
23:01-24:00, Fri., 26 May. 0.0392 0.0336 0.0357
22:01-23:00, Fri., 26 May. 0.0395 0.0329 0.0356
21:01-22:00, Fri., 26 May. 0.0388 0.0340 0.0357
20:01-21:00, Fri., 26 May. 0.0370 0.0335 0.0354
19:01-20:00, Fri., 26 May. 0.0387 0.0340 0.0356
18:01-19:00, Fri., 26 May. 0.0373 0.0338 0.0356
17:01-18:00, Fri., 26 May. 0.0388 0.0336 0.0358
16:01-17:00, Fri., 26 May. 0.0376 0.0334 0.0356
15:01-16:00, Fri., 26 May. 0.0376 0.0335 0.0355
14:01-15:00, Fri., 26 May. 0.0380 0.0328 0.0350
13:01-14:00, Fri., 26 May. 0.0376 0.0333 0.0353
12:01-13:00, Fri., 26 May. 0.0369 0.0327 0.0349
11:01-12:00, Fri., 26 May. 0.0383 0.0325 0.0351
10:01-11:00, Fri., 26 May. 0.0373 0.0331 0.0352
09:01-10:00, Fri., 26 May. 0.0376 0.0335 0.0352
08:01-09:00, Fri., 26 May. 0.0379 0.0331 0.0357
07:01-08:00, Fri., 26 May. 0.0380 0.0344 0.0359
06:01-07:00, Fri., 26 May. 0.0388 0.0339 0.0357
05:01-06:00, Fri., 26 May. 0.0373 0.0337 0.0358
04:01-05:00, Fri., 26 May. 0.0382 0.0331 0.0356
03:01-04:00, Fri., 26 May. 0.0387 0.0343 0.0359
02:01-03:00, Fri., 26 May. 0.0388 0.0339 0.0358
01:01-02:00, Fri., 26 May. 0.0370 0.0331 0.0354
00:01-01:00, Fri., 26 May. 0.0388 0.0339 0.0358
23:01-24:00, Thu., 25 May. 0.0384 0.0339 0.0356
22:01-23:00, Thu., 25 May. 0.0395 0.0337 0.0357
21:01-22:00, Thu., 25 May. 0.0394 0.0327 0.0358
20:01-21:00, Thu., 25 May. 0.0377 0.0335 0.0358
19:01-20:00, Thu., 25 May. 0.0374 0.0338 0.0357
18:01-19:00, Thu., 25 May. 0.0374 0.0336 0.0358
17:01-18:00, Thu., 25 May. 0.0392 0.0335 0.0356
16:01-17:00, Thu., 25 May. 0.0381 0.0333 0.0356
15:01-16:00, Thu., 25 May. 0.0379 0.0334 0.0356
14:01-15:00, Thu., 25 May. 0.0379 0.0331 0.0356
13:01-14:00, Thu., 25 May. 0.0378 0.0337 0.0356
12:01-13:00, Thu., 25 May. 0.0376 0.0339 0.0357
11:01-12:00, Thu., 25 May. 0.0394 0.0340 0.0360
10:01-11:00, Thu., 25 May. 0.0388 0.0341 0.0361
09:01-10:00, Thu., 25 May. 0.0392 0.0329 0.0361
08:01-09:00, Thu., 25 May. 0.0401 0.0337 0.0362
07:01-08:00, Thu., 25 May. 0.0391 0.0348 0.0362
06:01-07:00, Thu., 25 May. 0.0388 0.0348 0.0362
05:01-06:00, Thu., 25 May. 0.0380 0.0345 0.0360
04:01-05:00, Thu., 25 May. 0.0382 0.0343 0.0358
03:01-04:00, Thu., 25 May. 0.0374 0.0334 0.0356
02:01-03:00, Thu., 25 May. 0.0372 0.0335 0.0355
01:01-02:00, Thu., 25 May. 0.0396 0.0330 0.0358
00:01-01:00, Thu., 25 May. 0.0375 0.0328 0.0356
23:01-24:00, Wed., 24 May. 0.0384 0.0340 0.0359
22:01-23:00, Wed., 24 May. 0.0380 0.0336 0.0359
21:01-22:00, Wed., 24 May. 0.0402 0.0338 0.0358
20:01-21:00, Wed., 24 May. 0.0383 0.0339 0.0358
19:01-20:00, Wed., 24 May. 0.0375 0.0337 0.0356
18:01-19:00, Wed., 24 May. 0.0385 0.0338 0.0359
17:01-18:00, Wed., 24 May. 0.0370 0.0336 0.0355
16:01-17:00, Wed., 24 May. 0.0387 0.0329 0.0357
15:01-16:00, Wed., 24 May. 0.0384 0.0335 0.0358
14:01-15:00, Wed., 24 May. 0.0385 0.0331 0.0356
13:01-14:00, Wed., 24 May. 0.0385 0.0340 0.0358
12:01-13:00, Wed., 24 May. 0.0380 0.0336 0.0358
11:01-12:00, Wed., 24 May. 0.0374 0.0334 0.0354
10:01-11:00, Wed., 24 May. 0.0401 0.0334 0.0357
09:01-10:00, Wed., 24 May. 0.0390 0.0335 0.0355
08:01-09:00, Wed., 24 May. 0.0372 0.0330 0.0354
07:01-08:00, Wed., 24 May. 0.0382 0.0343 0.0358
06:01-07:00, Wed., 24 May. 0.0414 0.0333 0.0360
05:01-06:00, Wed., 24 May. 0.0400 0.0333 0.0352
04:01-05:00, Wed., 24 May. 0.0394 0.0340 0.0357
03:01-04:00, Wed., 24 May. 0.0380 0.0325 0.0355
02:01-03:00, Wed., 24 May. 0.0386 0.0328 0.0357
01:01-02:00, Wed., 24 May. 0.0382 0.0335 0.0358
00:01-01:00, Wed., 24 May. 0.0381 0.0329 0.0361
23:01-24:00, Tue., 23 May. 0.0411 0.0346 0.0375
22:01-23:00, Tue., 23 May. 0.0487 0.0362 0.0420
21:01-22:00, Tue., 23 May. 0.0504 0.0370 0.0429
20:01-21:00, Tue., 23 May. 0.0389 0.0341 0.0364
19:01-20:00, Tue., 23 May. 0.0404 0.0335 0.0363
18:01-19:00, Tue., 23 May. 0.0382 0.0341 0.0362
17:01-18:00, Tue., 23 May. 0.0417 0.0352 0.0373