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, Mon., 11 Dec. 0.0394 0.0343 0.0367
10:01-11:00, Mon., 11 Dec. 0.0404 0.0350 0.0376
09:01-10:00, Mon., 11 Dec. 0.0411 0.0354 0.0378
08:01-09:00, Mon., 11 Dec. 0.0410 0.0346 0.0372
07:01-08:00, Mon., 11 Dec. 0.0385 0.0333 0.0356
06:01-07:00, Mon., 11 Dec. 0.0371 0.0341 0.0356
05:01-06:00, Mon., 11 Dec. 0.0374 0.0342 0.0358
04:01-05:00, Mon., 11 Dec. 0.0397 0.0345 0.0363
03:01-04:00, Mon., 11 Dec. 0.0391 0.0337 0.0359
02:01-03:00, Mon., 11 Dec. 0.0390 0.0339 0.0358
01:01-02:00, Mon., 11 Dec. 0.0372 0.0328 0.0354
00:01-01:00, Mon., 11 Dec. 0.0376 0.0339 0.0357
23:01-24:00, Sun., 10 Dec. 0.0390 0.0343 0.0360
22:01-23:00, Sun., 10 Dec. 0.0383 0.0335 0.0359
21:01-22:00, Sun., 10 Dec. 0.0393 0.0336 0.0359
20:01-21:00, Sun., 10 Dec. 0.0382 0.0340 0.0360
19:01-20:00, Sun., 10 Dec. 0.0374 0.0334 0.0358
18:01-19:00, Sun., 10 Dec. 0.0385 0.0327 0.0359
17:01-18:00, Sun., 10 Dec. 0.0387 0.0339 0.0356
16:01-17:00, Sun., 10 Dec. 0.0404 0.0339 0.0359
15:01-16:00, Sun., 10 Dec. 0.0378 0.0339 0.0357
14:01-15:00, Sun., 10 Dec. 0.0386 0.0341 0.0359
13:01-14:00, Sun., 10 Dec. 0.0388 0.0342 0.0363
12:01-13:00, Sun., 10 Dec. 0.0401 0.0350 0.0367
11:01-12:00, Sun., 10 Dec. 0.0399 0.0348 0.0369
10:01-11:00, Sun., 10 Dec. 0.0392 0.0352 0.0369
09:01-10:00, Sun., 10 Dec. 0.0412 0.0353 0.0371
08:01-09:00, Sun., 10 Dec. 0.0406 0.0350 0.0370
07:01-08:00, Sun., 10 Dec. 0.0385 0.0345 0.0366
06:01-07:00, Sun., 10 Dec. 0.0385 0.0349 0.0364
05:01-06:00, Sun., 10 Dec. 0.0390 0.0349 0.0366
04:01-05:00, Sun., 10 Dec. 0.0387 0.0344 0.0364
03:01-04:00, Sun., 10 Dec. 0.0386 0.0338 0.0363
02:01-03:00, Sun., 10 Dec. 0.0393 0.0348 0.0365
01:01-02:00, Sun., 10 Dec. 0.0389 0.0341 0.0365
00:01-01:00, Sun., 10 Dec. 0.0407 0.0335 0.0362
23:01-24:00, Sat., 09 Dec. 0.0405 0.0336 0.0360
22:01-23:00, Sat., 09 Dec. 0.0386 0.0343 0.0359
21:01-22:00, Sat., 09 Dec. 0.0396 0.0339 0.0360
20:01-21:00, Sat., 09 Dec. 0.0391 0.0343 0.0359
19:01-20:00, Sat., 09 Dec. 0.0382 0.0339 0.0358
18:01-19:00, Sat., 09 Dec. 0.0382 0.0341 0.0360
17:01-18:00, Sat., 09 Dec. 0.0380 0.0337 0.0359
16:01-17:00, Sat., 09 Dec. 0.0383 0.0336 0.0358
15:01-16:00, Sat., 09 Dec. 0.0373 0.0337 0.0357
14:01-15:00, Sat., 09 Dec. 0.0377 0.0338 0.0358
13:01-14:00, Sat., 09 Dec. 0.0375 0.0333 0.0357
12:01-13:00, Sat., 09 Dec. 0.0394 0.0336 0.0359
11:01-12:00, Sat., 09 Dec. 0.0372 0.0338 0.0359
10:01-11:00, Sat., 09 Dec. 0.0379 0.0343 0.0361
09:01-10:00, Sat., 09 Dec. 0.0381 0.0346 0.0361
08:01-09:00, Sat., 09 Dec. 0.0383 0.0334 0.0359
07:01-08:00, Sat., 09 Dec. 0.0388 0.0341 0.0358
06:01-07:00, Sat., 09 Dec. 0.0372 0.0334 0.0356
05:01-06:00, Sat., 09 Dec. 0.0374 0.0335 0.0355
04:01-05:00, Sat., 09 Dec. 0.0379 0.0334 0.0358
03:01-04:00, Sat., 09 Dec. 0.0381 0.0336 0.0359
02:01-03:00, Sat., 09 Dec. 0.0379 0.0336 0.0358
01:01-02:00, Sat., 09 Dec. 0.0396 0.0342 0.0361
00:01-01:00, Sat., 09 Dec. 0.0391 0.0344 0.0361
23:01-24:00, Fri., 08 Dec. 0.0396 0.0351 0.0370
22:01-23:00, Fri., 08 Dec. 0.0431 0.0370 0.0398
21:01-22:00, Fri., 08 Dec. 0.0467 0.0375 0.0423
20:01-21:00, Fri., 08 Dec. 0.0493 0.0421 0.0455
19:01-20:00, Fri., 08 Dec. 0.0472 0.0398 0.0433
18:01-19:00, Fri., 08 Dec. 0.0447 0.0367 0.0407
17:01-18:00, Fri., 08 Dec. 0.0411 0.0350 0.0374
16:01-17:00, Fri., 08 Dec. 0.0406 0.0358 0.0376
15:01-16:00, Fri., 08 Dec. 0.0416 0.0352 0.0375
14:01-15:00, Fri., 08 Dec. 0.0402 0.0351 0.0373
13:01-14:00, Fri., 08 Dec. 0.0403 0.0349 0.0371
12:01-13:00, Fri., 08 Dec. 0.0406 0.0345 0.0372
11:01-12:00, Fri., 08 Dec. 0.0399 0.0346 0.0367
10:01-11:00, Fri., 08 Dec. 0.0394 0.0352 0.0368
09:01-10:00, Fri., 08 Dec. 0.0414 0.0352 0.0367
08:01-09:00, Fri., 08 Dec. 0.0415 0.0350 0.0370
07:01-08:00, Fri., 08 Dec. 0.0410 0.0351 0.0371
06:01-07:00, Fri., 08 Dec. 0.0395 0.0351 0.0369
05:01-06:00, Fri., 08 Dec. 0.0408 0.0347 0.0370
04:01-05:00, Fri., 08 Dec. 0.0396 0.0347 0.0367
03:01-04:00, Fri., 08 Dec. 0.0389 0.0349 0.0368
02:01-03:00, Fri., 08 Dec. 0.0390 0.0348 0.0365
01:01-02:00, Fri., 08 Dec. 0.0388 0.0349 0.0366
00:01-01:00, Fri., 08 Dec. 0.0398 0.0351 0.0368
23:01-24:00, Thu., 07 Dec. 0.0386 0.0344 0.0366
22:01-23:00, Thu., 07 Dec. 0.0381 0.0341 0.0360
21:01-22:00, Thu., 07 Dec. 0.0391 0.0341 0.0362
20:01-21:00, Thu., 07 Dec. 0.0399 0.0333 0.0362
19:01-20:00, Thu., 07 Dec. 0.0395 0.0341 0.0361
18:01-19:00, Thu., 07 Dec. 0.0389 0.0342 0.0363
17:01-18:00, Thu., 07 Dec. 0.0396 0.0346 0.0363
16:01-17:00, Thu., 07 Dec. 0.0392 0.0339 0.0362
15:01-16:00, Thu., 07 Dec. 0.0390 0.0340 0.0362
14:01-15:00, Thu., 07 Dec. 0.0397 0.0342 0.0363
13:01-14:00, Thu., 07 Dec. 0.0388 0.0351 0.0364
12:01-13:00, Thu., 07 Dec. 0.0408 0.0344 0.0366
11:01-12:00, Thu., 07 Dec. 0.0396 0.0345 0.0365
10:01-11:00, Thu., 07 Dec. 0.0401 0.0343 0.0369
09:01-10:00, Thu., 07 Dec. 0.0413 0.0353 0.0372
08:01-09:00, Thu., 07 Dec. 0.0393 0.0347 0.0367
07:01-08:00, Thu., 07 Dec. 0.0392 0.0353 0.0367
06:01-07:00, Thu., 07 Dec. 0.0402 0.0348 0.0369
05:01-06:00, Thu., 07 Dec. 0.0394 0.0343 0.0367
04:01-05:00, Thu., 07 Dec. 0.0404 0.0346 0.0365
03:01-04:00, Thu., 07 Dec. 0.0379 0.0342 0.0362
02:01-03:00, Thu., 07 Dec. 0.0390 0.0338 0.0363
01:01-02:00, Thu., 07 Dec. 0.0394 0.0346 0.0365
00:01-01:00, Thu., 07 Dec. 0.0384 0.0344 0.0363
23:01-24:00, Wed., 06 Dec. 0.0394 0.0346 0.0363
22:01-23:00, Wed., 06 Dec. 0.0391 0.0347 0.0363
21:01-22:00, Wed., 06 Dec. 0.0388 0.0340 0.0362
20:01-21:00, Wed., 06 Dec. 0.0391 0.0341 0.0361
19:01-20:00, Wed., 06 Dec. 0.0388 0.0337 0.0361
18:01-19:00, Wed., 06 Dec. 0.0387 0.0344 0.0363
17:01-18:00, Wed., 06 Dec. 0.0389 0.0342 0.0362
16:01-17:00, Wed., 06 Dec. 0.0391 0.0344 0.0362
15:01-16:00, Wed., 06 Dec. 0.0401 0.0345 0.0362
14:01-15:00, Wed., 06 Dec. 0.0389 0.0340 0.0363
13:01-14:00, Wed., 06 Dec. 0.0401 0.0342 0.0362
12:01-13:00, Wed., 06 Dec. 0.0398 0.0338 0.0363
11:01-12:00, Wed., 06 Dec. 0.0396 0.0346 0.0362
10:01-11:00, Wed., 06 Dec. 0.0410 0.0343 0.0364
09:01-10:00, Wed., 06 Dec. 0.0385 0.0341 0.0364
08:01-09:00, Wed., 06 Dec. 0.0383 0.0344 0.0363
07:01-08:00, Wed., 06 Dec. 0.0384 0.0338 0.0362
06:01-07:00, Wed., 06 Dec. 0.0378 0.0345 0.0361
05:01-06:00, Wed., 06 Dec. 0.0381 0.0339 0.0361
04:01-05:00, Wed., 06 Dec. 0.0376 0.0337 0.0361
03:01-04:00, Wed., 06 Dec. 0.0394 0.0340 0.0360
02:01-03:00, Wed., 06 Dec. 0.0397 0.0340 0.0360
01:01-02:00, Wed., 06 Dec. 0.0373 0.0333 0.0357
00:01-01:00, Wed., 06 Dec. 0.0383 0.0340 0.0358
23:01-24:00, Tue., 05 Dec. 0.0375 0.0341 0.0357
22:01-23:00, Tue., 05 Dec. 0.0388 0.0337 0.0359
21:01-22:00, Tue., 05 Dec. 0.0376 0.0335 0.0357
20:01-21:00, Tue., 05 Dec. 0.0374 0.0339 0.0358
19:01-20:00, Tue., 05 Dec. 0.0393 0.0339 0.0356
18:01-19:00, Tue., 05 Dec. 0.0394 0.0334 0.0357
17:01-18:00, Tue., 05 Dec. 0.0375 0.0333 0.0358
16:01-17:00, Tue., 05 Dec. 0.0380 0.0342 0.0359
15:01-16:00, Tue., 05 Dec. 0.0396 0.0338 0.0355
14:01-15:00, Tue., 05 Dec. 0.0388 0.0338 0.0360
13:01-14:00, Tue., 05 Dec. 0.0400 0.0340 0.0361
12:01-13:00, Tue., 05 Dec. 0.0396 0.0338 0.0363
11:01-12:00, Tue., 05 Dec. 0.0388 0.0344 0.0364
10:01-11:00, Tue., 05 Dec. 0.0400 0.0344 0.0367
09:01-10:00, Tue., 05 Dec. 0.0397 0.0346 0.0368
08:01-09:00, Tue., 05 Dec. 0.0391 0.0347 0.0365
07:01-08:00, Tue., 05 Dec. 0.0399 0.0344 0.0365
06:01-07:00, Tue., 05 Dec. 0.0395 0.0351 0.0366
05:01-06:00, Tue., 05 Dec. 0.0403 0.0345 0.0368
04:01-05:00, Tue., 05 Dec. 0.0400 0.0349 0.0367
03:01-04:00, Tue., 05 Dec. 0.0388 0.0343 0.0363
02:01-03:00, Tue., 05 Dec. 0.0383 0.0346 0.0364
01:01-02:00, Tue., 05 Dec. 0.0376 0.0342 0.0362
00:01-01:00, Tue., 05 Dec. 0.0395 0.0344 0.0364
23:01-24:00, Mon., 04 Dec. 0.0384 0.0345 0.0362
22:01-23:00, Mon., 04 Dec. 0.0388 0.0345 0.0365
21:01-22:00, Mon., 04 Dec. 0.0376 0.0341 0.0361
20:01-21:00, Mon., 04 Dec. 0.0407 0.0346 0.0371
19:01-20:00, Mon., 04 Dec. 0.0411 0.0350 0.0371
18:01-19:00, Mon., 04 Dec. 0.0391 0.0338 0.0364
17:01-18:00, Mon., 04 Dec. 0.0382 0.0348 0.0363
16:01-17:00, Mon., 04 Dec. 0.0411 0.0330 0.0363
15:01-16:00, Mon., 04 Dec. 0.0395 0.0343 0.0362
14:01-15:00, Mon., 04 Dec. 0.0385 0.0342 0.0363
13:01-14:00, Mon., 04 Dec. 0.0385 0.0337 0.0363
12:01-13:00, Mon., 04 Dec. 0.0395 0.0345 0.0367
11:01-12:00, Mon., 04 Dec. 0.0398 0.0339 0.0368
10:01-11:00, Mon., 04 Dec. 0.0400 0.0352 0.0370
09:01-10:00, Mon., 04 Dec. 0.0398 0.0355 0.0373
08:01-09:00, Mon., 04 Dec. 0.0402 0.0346 0.0370
07:01-08:00, Mon., 04 Dec. 0.0400 0.0344 0.0369
06:01-07:00, Mon., 04 Dec. 0.0399 0.0350 0.0370
05:01-06:00, Mon., 04 Dec. 0.0394 0.0333 0.0366
04:01-05:00, Mon., 04 Dec. 0.0414 0.0345 0.0364
03:01-04:00, Mon., 04 Dec. 0.0397 0.0337 0.0360
02:01-03:00, Mon., 04 Dec. 0.0380 0.0340 0.0359
01:01-02:00, Mon., 04 Dec. 0.0375 0.0339 0.0359
00:01-01:00, Mon., 04 Dec. 0.0396 0.0343 0.0365
23:01-24:00, Sun., 03 Dec. 0.0422 0.0342 0.0367
22:01-23:00, Sun., 03 Dec. 0.0392 0.0345 0.0364
21:01-22:00, Sun., 03 Dec. 0.0404 0.0330 0.0364
20:01-21:00, Sun., 03 Dec. 0.0386 0.0339 0.0362
19:01-20:00, Sun., 03 Dec. 0.0394 0.0343 0.0362
18:01-19:00, Sun., 03 Dec. 0.0394 0.0345 0.0364
17:01-18:00, Sun., 03 Dec. 0.0381 0.0344 0.0362
16:01-17:00, Sun., 03 Dec. 0.0381 0.0343 0.0360
15:01-16:00, Sun., 03 Dec. 0.0391 0.0342 0.0363
14:01-15:00, Sun., 03 Dec. 0.0383 0.0344 0.0361
13:01-14:00, Sun., 03 Dec. 0.0398 0.0344 0.0363
12:01-13:00, Sun., 03 Dec. 0.0381 0.0345 0.0362
11:01-12:00, Sun., 03 Dec. 0.0381 0.0338 0.0365
10:01-11:00, Sun., 03 Dec. 0.0398 0.0342 0.0364
09:01-10:00, Sun., 03 Dec. 0.0392 0.0350 0.0366
08:01-09:00, Sun., 03 Dec. 0.0396 0.0349 0.0366
07:01-08:00, Sun., 03 Dec. 0.0386 0.0346 0.0365
06:01-07:00, Sun., 03 Dec. 0.0394 0.0340 0.0362
05:01-06:00, Sun., 03 Dec. 0.0392 0.0343 0.0363
04:01-05:00, Sun., 03 Dec. 0.0381 0.0346 0.0360
03:01-04:00, Sun., 03 Dec. 0.0392 0.0348 0.0364
02:01-03:00, Sun., 03 Dec. 0.0388 0.0342 0.0361
01:01-02:00, Sun., 03 Dec. 0.0383 0.0339 0.0357
00:01-01:00, Sun., 03 Dec. 0.0375 0.0333 0.0357
23:01-24:00, Sat., 02 Dec. 0.0393 0.0334 0.0359
22:01-23:00, Sat., 02 Dec. 0.0374 0.0333 0.0357
21:01-22:00, Sat., 02 Dec. 0.0383 0.0331 0.0357
20:01-21:00, Sat., 02 Dec. 0.0379 0.0334 0.0357
19:01-20:00, Sat., 02 Dec. 0.0392 0.0334 0.0358
18:01-19:00, Sat., 02 Dec. 0.0372 0.0337 0.0358
17:01-18:00, Sat., 02 Dec. 0.0379 0.0339 0.0355
16:01-17:00, Sat., 02 Dec. 0.0377 0.0339 0.0359
15:01-16:00, Sat., 02 Dec. 0.0383 0.0339 0.0359
14:01-15:00, Sat., 02 Dec. 0.0376 0.0340 0.0356
13:01-14:00, Sat., 02 Dec. 0.0378 0.0343 0.0358
12:01-13:00, Sat., 02 Dec. 0.0381 0.0339 0.0358
11:01-12:00, Sat., 02 Dec. 0.0387 0.0337 0.0359
10:01-11:00, Sat., 02 Dec. 0.0390 0.0339 0.0358
09:01-10:00, Sat., 02 Dec. 0.0374 0.0341 0.0358
08:01-09:00, Sat., 02 Dec. 0.0388 0.0343 0.0360
07:01-08:00, Sat., 02 Dec. 0.0375 0.0345 0.0358
06:01-07:00, Sat., 02 Dec. 0.0373 0.0339 0.0357
05:01-06:00, Sat., 02 Dec. 0.0378 0.0335 0.0357
04:01-05:00, Sat., 02 Dec. 0.0404 0.0341 0.0359
03:01-04:00, Sat., 02 Dec. 0.0376 0.0336 0.0357
02:01-03:00, Sat., 02 Dec. 0.0378 0.0342 0.0359
01:01-02:00, Sat., 02 Dec. 0.0387 0.0335 0.0358
00:01-01:00, Sat., 02 Dec. 0.0380 0.0342 0.0360
23:01-24:00, Fri., 01 Dec. 0.0381 0.0337 0.0361
22:01-23:00, Fri., 01 Dec. 0.0374 0.0348 0.0361
21:01-22:00, Fri., 01 Dec. 0.0384 0.0340 0.0358
20:01-21:00, Fri., 01 Dec. 0.0383 0.0336 0.0358
19:01-20:00, Fri., 01 Dec. 0.0385 0.0329 0.0358
18:01-19:00, Fri., 01 Dec. 0.0384 0.0335 0.0360
17:01-18:00, Fri., 01 Dec. 0.0380 0.0345 0.0360
16:01-17:00, Fri., 01 Dec. 0.0394 0.0332 0.0362
15:01-16:00, Fri., 01 Dec. 0.0388 0.0340 0.0359
14:01-15:00, Fri., 01 Dec. 0.0398 0.0337 0.0362
13:01-14:00, Fri., 01 Dec. 0.0388 0.0349 0.0365
12:01-13:00, Fri., 01 Dec. 0.0406 0.0360 0.0376