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

Due to a power outage at our center due to statutory inspection of electrical equipment, we will temporarily suspend updating of monitoring post measurement values ​​from 8:00 to 19:00 on Saturday, October 18, 2025.

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
06:01-07:00, Sun., 14 Sep. 0.0380 0.0337 0.0363
05:01-06:00, Sun., 14 Sep. 0.0385 0.0344 0.0364
04:01-05:00, Sun., 14 Sep. 0.0384 0.0346 0.0363
03:01-04:00, Sun., 14 Sep. 0.0385 0.0340 0.0362
02:01-03:00, Sun., 14 Sep. 0.0387 0.0343 0.0363
01:01-02:00, Sun., 14 Sep. 0.0385 0.0340 0.0361
00:01-01:00, Sun., 14 Sep. 0.0389 0.0340 0.0361
23:01-24:00, Sat., 13 Sep. 0.0380 0.0333 0.0361
22:01-23:00, Sat., 13 Sep. 0.0387 0.0347 0.0364
21:01-22:00, Sat., 13 Sep. 0.0386 0.0340 0.0366
20:01-21:00, Sat., 13 Sep. 0.0387 0.0340 0.0368
19:01-20:00, Sat., 13 Sep. 0.0388 0.0346 0.0364
18:01-19:00, Sat., 13 Sep. 0.0391 0.0334 0.0364
17:01-18:00, Sat., 13 Sep. 0.0385 0.0340 0.0363
16:01-17:00, Sat., 13 Sep. 0.0378 0.0338 0.0360
15:01-16:00, Sat., 13 Sep. 0.0386 0.0343 0.0362
14:01-15:00, Sat., 13 Sep. 0.0384 0.0335 0.0362
13:01-14:00, Sat., 13 Sep. 0.0381 0.0342 0.0362
12:01-13:00, Sat., 13 Sep. 0.0387 0.0340 0.0361
11:01-12:00, Sat., 13 Sep. 0.0382 0.0335 0.0360
10:01-11:00, Sat., 13 Sep. 0.0381 0.0338 0.0359
09:01-10:00, Sat., 13 Sep. 0.0381 0.0335 0.0358
08:01-09:00, Sat., 13 Sep. 0.0379 0.0335 0.0360
07:01-08:00, Sat., 13 Sep. 0.0384 0.0341 0.0357
06:01-07:00, Sat., 13 Sep. 0.0372 0.0332 0.0356
05:01-06:00, Sat., 13 Sep. 0.0388 0.0340 0.0360
04:01-05:00, Sat., 13 Sep. 0.0398 0.0345 0.0372
03:01-04:00, Sat., 13 Sep. 0.0432 0.0364 0.0407
02:01-03:00, Sat., 13 Sep. 0.0445 0.0371 0.0409
01:01-02:00, Sat., 13 Sep. 0.0400 0.0354 0.0383
00:01-01:00, Sat., 13 Sep. 0.0386 0.0347 0.0366
23:01-24:00, Fri., 12 Sep. 0.0379 0.0340 0.0361
22:01-23:00, Fri., 12 Sep. 0.0395 0.0347 0.0368
21:01-22:00, Fri., 12 Sep. 0.0381 0.0342 0.0364
20:01-21:00, Fri., 12 Sep. 0.0378 0.0337 0.0361
19:01-20:00, Fri., 12 Sep. 0.0385 0.0341 0.0363
18:01-19:00, Fri., 12 Sep. 0.0377 0.0336 0.0360
17:01-18:00, Fri., 12 Sep. 0.0384 0.0340 0.0360
16:01-17:00, Fri., 12 Sep. 0.0381 0.0343 0.0361
15:01-16:00, Fri., 12 Sep. 0.0390 0.0333 0.0360
14:01-15:00, Fri., 12 Sep. 0.0385 0.0347 0.0363
13:01-14:00, Fri., 12 Sep. 0.0387 0.0336 0.0365
12:01-13:00, Fri., 12 Sep. 0.0385 0.0342 0.0367
11:01-12:00, Fri., 12 Sep. 0.0385 0.0329 0.0362
10:01-11:00, Fri., 12 Sep. 0.0378 0.0343 0.0359
09:01-10:00, Fri., 12 Sep. 0.0384 0.0335 0.0357
08:01-09:00, Fri., 12 Sep. 0.0371 0.0340 0.0358
07:01-08:00, Fri., 12 Sep. 0.0382 0.0336 0.0360
06:01-07:00, Fri., 12 Sep. 0.0388 0.0332 0.0360
05:01-06:00, Fri., 12 Sep. 0.0378 0.0342 0.0358
04:01-05:00, Fri., 12 Sep. 0.0388 0.0340 0.0358
03:01-04:00, Fri., 12 Sep. 0.0382 0.0343 0.0363
02:01-03:00, Fri., 12 Sep. 0.0424 0.0355 0.0386
01:01-02:00, Fri., 12 Sep. 0.0461 0.0375 0.0422
00:01-01:00, Fri., 12 Sep. 0.0436 0.0363 0.0396
23:01-24:00, Thu., 11 Sep. 0.0390 0.0341 0.0370
22:01-23:00, Thu., 11 Sep. 0.0382 0.0337 0.0358
21:01-22:00, Thu., 11 Sep. 0.0382 0.0340 0.0357
20:01-21:00, Thu., 11 Sep. 0.0378 0.0343 0.0359
19:01-20:00, Thu., 11 Sep. 0.0394 0.0335 0.0364
18:01-19:00, Thu., 11 Sep. 0.0399 0.0347 0.0371
17:01-18:00, Thu., 11 Sep. 0.0408 0.0353 0.0378
16:01-17:00, Thu., 11 Sep. 0.0465 0.0381 0.0424
15:01-16:00, Thu., 11 Sep. 0.0467 0.0357 0.0418
14:01-15:00, Thu., 11 Sep. 0.0384 0.0343 0.0367
13:01-14:00, Thu., 11 Sep. 0.0396 0.0342 0.0366
12:01-13:00, Thu., 11 Sep. 0.0391 0.0343 0.0365
11:01-12:00, Thu., 11 Sep. 0.0397 0.0346 0.0362
10:01-11:00, Thu., 11 Sep. 0.0381 0.0350 0.0367
09:01-10:00, Thu., 11 Sep. 0.0384 0.0337 0.0362
08:01-09:00, Thu., 11 Sep. 0.0386 0.0340 0.0365
07:01-08:00, Thu., 11 Sep. 0.0383 0.0347 0.0364
06:01-07:00, Thu., 11 Sep. 0.0387 0.0339 0.0363
05:01-06:00, Thu., 11 Sep. 0.0386 0.0342 0.0364
04:01-05:00, Thu., 11 Sep. 0.0381 0.0347 0.0364
03:01-04:00, Thu., 11 Sep. 0.0385 0.0344 0.0364
02:01-03:00, Thu., 11 Sep. 0.0384 0.0347 0.0366
01:01-02:00, Thu., 11 Sep. 0.0390 0.0340 0.0367
00:01-01:00, Thu., 11 Sep. 0.0388 0.0342 0.0365
23:01-24:00, Wed., 10 Sep. 0.0384 0.0336 0.0364
22:01-23:00, Wed., 10 Sep. 0.0391 0.0335 0.0364
21:01-22:00, Wed., 10 Sep. 0.0391 0.0345 0.0363
20:01-21:00, Wed., 10 Sep. 0.0387 0.0347 0.0366
19:01-20:00, Wed., 10 Sep. 0.0391 0.0345 0.0365
18:01-19:00, Wed., 10 Sep. 0.0383 0.0335 0.0362
17:01-18:00, Wed., 10 Sep. 0.0390 0.0342 0.0365
16:01-17:00, Wed., 10 Sep. 0.0384 0.0343 0.0363
15:01-16:00, Wed., 10 Sep. 0.0379 0.0342 0.0364
14:01-15:00, Wed., 10 Sep. 0.0383 0.0346 0.0366
13:01-14:00, Wed., 10 Sep. 0.0389 0.0339 0.0368
12:01-13:00, Wed., 10 Sep. 0.0397 0.0348 0.0369
11:01-12:00, Wed., 10 Sep. 0.0387 0.0348 0.0367
10:01-11:00, Wed., 10 Sep. 0.0388 0.0347 0.0367
09:01-10:00, Wed., 10 Sep. 0.0398 0.0349 0.0370
08:01-09:00, Wed., 10 Sep. 0.0388 0.0350 0.0369
07:01-08:00, Wed., 10 Sep. 0.0390 0.0349 0.0371
06:01-07:00, Wed., 10 Sep. 0.0397 0.0347 0.0370
05:01-06:00, Wed., 10 Sep. 0.0398 0.0345 0.0370
04:01-05:00, Wed., 10 Sep. 0.0391 0.0348 0.0370
03:01-04:00, Wed., 10 Sep. 0.0399 0.0351 0.0371
02:01-03:00, Wed., 10 Sep. 0.0383 0.0350 0.0369
01:01-02:00, Wed., 10 Sep. 0.0390 0.0344 0.0370
00:01-01:00, Wed., 10 Sep. 0.0389 0.0356 0.0369
23:01-24:00, Tue., 09 Sep. 0.0394 0.0349 0.0372
22:01-23:00, Tue., 09 Sep. 0.0398 0.0350 0.0369
21:01-22:00, Tue., 09 Sep. 0.0391 0.0345 0.0368
20:01-21:00, Tue., 09 Sep. 0.0396 0.0350 0.0367
19:01-20:00, Tue., 09 Sep. 0.0391 0.0346 0.0367
18:01-19:00, Tue., 09 Sep. 0.0387 0.0334 0.0370
17:01-18:00, Tue., 09 Sep. 0.0391 0.0350 0.0368
16:01-17:00, Tue., 09 Sep. 0.0380 0.0350 0.0368
15:01-16:00, Tue., 09 Sep. 0.0388 0.0350 0.0368
14:01-15:00, Tue., 09 Sep. 0.0385 0.0350 0.0367
13:01-14:00, Tue., 09 Sep. 0.0389 0.0323 0.0369
12:01-13:00, Tue., 09 Sep. 0.0395 0.0350 0.0370
11:01-12:00, Tue., 09 Sep. 0.0387 0.0347 0.0366
10:01-11:00, Tue., 09 Sep. 0.0394 0.0340 0.0368
09:01-10:00, Tue., 09 Sep. 0.0384 0.0353 0.0368
08:01-09:00, Tue., 09 Sep. 0.0389 0.0349 0.0369
07:01-08:00, Tue., 09 Sep. 0.0386 0.0347 0.0368
06:01-07:00, Tue., 09 Sep. 0.0403 0.0350 0.0371
05:01-06:00, Tue., 09 Sep. 0.0388 0.0350 0.0368
04:01-05:00, Tue., 09 Sep. 0.0388 0.0354 0.0368
03:01-04:00, Tue., 09 Sep. 0.0397 0.0342 0.0370
02:01-03:00, Tue., 09 Sep. 0.0404 0.0345 0.0369
01:01-02:00, Tue., 09 Sep. 0.0395 0.0347 0.0370
00:01-01:00, Tue., 09 Sep. 0.0398 0.0355 0.0371
23:01-24:00, Mon., 08 Sep. 0.0391 0.0351 0.0371
22:01-23:00, Mon., 08 Sep. 0.0390 0.0356 0.0371
21:01-22:00, Mon., 08 Sep. 0.0398 0.0347 0.0370
20:01-21:00, Mon., 08 Sep. 0.0390 0.0331 0.0367
19:01-20:00, Mon., 08 Sep. 0.0382 0.0353 0.0368
18:01-19:00, Mon., 08 Sep. 0.0395 0.0338 0.0367
17:01-18:00, Mon., 08 Sep. 0.0392 0.0335 0.0366
16:01-17:00, Mon., 08 Sep. 0.0392 0.0346 0.0366
15:01-16:00, Mon., 08 Sep. 0.0384 0.0346 0.0367
14:01-15:00, Mon., 08 Sep. 0.0399 0.0350 0.0366
13:01-14:00, Mon., 08 Sep. 0.0390 0.0344 0.0368
12:01-13:00, Mon., 08 Sep. 0.0392 0.0355 0.0370
11:01-12:00, Mon., 08 Sep. 0.0392 0.0348 0.0368
10:01-11:00, Mon., 08 Sep. 0.0382 0.0339 0.0364
09:01-10:00, Mon., 08 Sep. 0.0396 0.0336 0.0367
08:01-09:00, Mon., 08 Sep. 0.0392 0.0348 0.0367
07:01-08:00, Mon., 08 Sep. 0.0380 0.0345 0.0365
06:01-07:00, Mon., 08 Sep. 0.0392 0.0342 0.0367
05:01-06:00, Mon., 08 Sep. 0.0389 0.0341 0.0364
04:01-05:00, Mon., 08 Sep. 0.0386 0.0338 0.0365
03:01-04:00, Mon., 08 Sep. 0.0389 0.0337 0.0364
02:01-03:00, Mon., 08 Sep. 0.0381 0.0344 0.0363
01:01-02:00, Mon., 08 Sep. 0.0392 0.0347 0.0366
00:01-01:00, Mon., 08 Sep. 0.0384 0.0344 0.0365
23:01-24:00, Sun., 07 Sep. 0.0381 0.0340 0.0364
22:01-23:00, Sun., 07 Sep. 0.0382 0.0347 0.0365
21:01-22:00, Sun., 07 Sep. 0.0398 0.0347 0.0368
20:01-21:00, Sun., 07 Sep. 0.0384 0.0347 0.0366
19:01-20:00, Sun., 07 Sep. 0.0385 0.0342 0.0365
18:01-19:00, Sun., 07 Sep. 0.0386 0.0341 0.0365
17:01-18:00, Sun., 07 Sep. 0.0387 0.0343 0.0364
16:01-17:00, Sun., 07 Sep. 0.0395 0.0340 0.0365
15:01-16:00, Sun., 07 Sep. 0.0385 0.0344 0.0366
14:01-15:00, Sun., 07 Sep. 0.0391 0.0347 0.0368
13:01-14:00, Sun., 07 Sep. 0.0388 0.0345 0.0367
12:01-13:00, Sun., 07 Sep. 0.0388 0.0348 0.0369
11:01-12:00, Sun., 07 Sep. 0.0391 0.0347 0.0368
10:01-11:00, Sun., 07 Sep. 0.0382 0.0340 0.0365
09:01-10:00, Sun., 07 Sep. 0.0395 0.0345 0.0366
08:01-09:00, Sun., 07 Sep. 0.0385 0.0346 0.0364
07:01-08:00, Sun., 07 Sep. 0.0388 0.0335 0.0362
06:01-07:00, Sun., 07 Sep. 0.0383 0.0339 0.0365
05:01-06:00, Sun., 07 Sep. 0.0379 0.0340 0.0362
04:01-05:00, Sun., 07 Sep. 0.0401 0.0347 0.0366
03:01-04:00, Sun., 07 Sep. 0.0383 0.0341 0.0364
02:01-03:00, Sun., 07 Sep. 0.0381 0.0343 0.0365
01:01-02:00, Sun., 07 Sep. 0.0385 0.0343 0.0365
00:01-01:00, Sun., 07 Sep. 0.0388 0.0339 0.0364
23:01-24:00, Sat., 06 Sep. 0.0382 0.0344 0.0365
22:01-23:00, Sat., 06 Sep. 0.0384 0.0346 0.0365
21:01-22:00, Sat., 06 Sep. 0.0391 0.0347 0.0366
20:01-21:00, Sat., 06 Sep. 0.0384 0.0344 0.0365
19:01-20:00, Sat., 06 Sep. 0.0391 0.0347 0.0367
18:01-19:00, Sat., 06 Sep. 0.0388 0.0340 0.0368
17:01-18:00, Sat., 06 Sep. 0.0384 0.0340 0.0364
16:01-17:00, Sat., 06 Sep. 0.0388 0.0346 0.0365
15:01-16:00, Sat., 06 Sep. 0.0389 0.0344 0.0366
14:01-15:00, Sat., 06 Sep. 0.0393 0.0347 0.0367
13:01-14:00, Sat., 06 Sep. 0.0391 0.0342 0.0366
12:01-13:00, Sat., 06 Sep. 0.0388 0.0344 0.0369
11:01-12:00, Sat., 06 Sep. 0.0388 0.0352 0.0367
10:01-11:00, Sat., 06 Sep. 0.0386 0.0336 0.0363
09:01-10:00, Sat., 06 Sep. 0.0381 0.0342 0.0362
08:01-09:00, Sat., 06 Sep. 0.0381 0.0335 0.0362
07:01-08:00, Sat., 06 Sep. 0.0384 0.0348 0.0365
06:01-07:00, Sat., 06 Sep. 0.0391 0.0339 0.0363
05:01-06:00, Sat., 06 Sep. 0.0388 0.0339 0.0361
04:01-05:00, Sat., 06 Sep. 0.0383 0.0342 0.0361
03:01-04:00, Sat., 06 Sep. 0.0380 0.0335 0.0361
02:01-03:00, Sat., 06 Sep. 0.0382 0.0340 0.0364
01:01-02:00, Sat., 06 Sep. 0.0382 0.0338 0.0361
00:01-01:00, Sat., 06 Sep. 0.0377 0.0346 0.0361
23:01-24:00, Fri., 05 Sep. 0.0383 0.0343 0.0363
22:01-23:00, Fri., 05 Sep. 0.0383 0.0339 0.0363
21:01-22:00, Fri., 05 Sep. 0.0383 0.0341 0.0360
20:01-21:00, Fri., 05 Sep. 0.0379 0.0340 0.0359
19:01-20:00, Fri., 05 Sep. 0.0378 0.0336 0.0357
18:01-19:00, Fri., 05 Sep. 0.0377 0.0340 0.0361
17:01-18:00, Fri., 05 Sep. 0.0383 0.0337 0.0363
16:01-17:00, Fri., 05 Sep. 0.0398 0.0343 0.0378
15:01-16:00, Fri., 05 Sep. 0.0402 0.0358 0.0379
14:01-15:00, Fri., 05 Sep. 0.0404 0.0359 0.0378
13:01-14:00, Fri., 05 Sep. 0.0381 0.0346 0.0365
12:01-13:00, Fri., 05 Sep. 0.0386 0.0343 0.0365
11:01-12:00, Fri., 05 Sep. 0.0388 0.0344 0.0364
10:01-11:00, Fri., 05 Sep. 0.0391 0.0347 0.0367
09:01-10:00, Fri., 05 Sep. 0.0388 0.0353 0.0367
08:01-09:00, Fri., 05 Sep. 0.0395 0.0344 0.0367
07:01-08:00, Fri., 05 Sep. 0.0384 0.0345 0.0364
06:01-07:00, Fri., 05 Sep. 0.0386 0.0343 0.0365
05:01-06:00, Fri., 05 Sep. 0.0387 0.0345 0.0368
04:01-05:00, Fri., 05 Sep. 0.0396 0.0353 0.0374
03:01-04:00, Fri., 05 Sep. 0.0391 0.0352 0.0374
02:01-03:00, Fri., 05 Sep. 0.0403 0.0350 0.0376
01:01-02:00, Fri., 05 Sep. 0.0391 0.0350 0.0373
00:01-01:00, Fri., 05 Sep. 0.0401 0.0353 0.0375
23:01-24:00, Thu., 04 Sep. 0.0393 0.0350 0.0374
22:01-23:00, Thu., 04 Sep. 0.0402 0.0356 0.0378
21:01-22:00, Thu., 04 Sep. 0.0395 0.0357 0.0375
20:01-21:00, Thu., 04 Sep. 0.0401 0.0357 0.0378
19:01-20:00, Thu., 04 Sep. 0.0395 0.0354 0.0377
18:01-19:00, Thu., 04 Sep. 0.0404 0.0358 0.0378
17:01-18:00, Thu., 04 Sep. 0.0399 0.0355 0.0379
16:01-17:00, Thu., 04 Sep. 0.0405 0.0360 0.0379
15:01-16:00, Thu., 04 Sep. 0.0404 0.0355 0.0380
14:01-15:00, Thu., 04 Sep. 0.0411 0.0359 0.0379
13:01-14:00, Thu., 04 Sep. 0.0396 0.0358 0.0380
12:01-13:00, Thu., 04 Sep. 0.0412 0.0364 0.0379
11:01-12:00, Thu., 04 Sep. 0.0404 0.0358 0.0378
10:01-11:00, Thu., 04 Sep. 0.0407 0.0360 0.0380
09:01-10:00, Thu., 04 Sep. 0.0400 0.0362 0.0381
08:01-09:00, Thu., 04 Sep. 0.0412 0.0356 0.0378
07:01-08:00, Thu., 04 Sep. 0.0403 0.0360 0.0384