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

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

The monitoring post (Hachioji station) stops the measurement for a blackout by the construction of facilities and the facilities check temporarily on the following date and time.
From 1 Saturday, August 16, 2025 around 8:00 a.m. to Sunday, August 17, 2025 around 8:00 a.m.
from 2 Sunday, October 26, 2025 around 7:00 a.m. to around 6:00 p.m.
from 3 Saturday, November 22, 2025 around 7:30 a.m. to around 8:00 a.m.

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, Mon., 18 Aug. 0.0369 0.0320 0.0347
15:01-16:00, Mon., 18 Aug. 0.0388 0.0329 0.0353
14:01-15:00, Mon., 18 Aug. 0.0375 0.0328 0.0352
13:01-14:00, Mon., 18 Aug. 0.0377 0.0329 0.0354
12:01-13:00, Mon., 18 Aug. 0.0367 0.0331 0.0353
11:01-12:00, Mon., 18 Aug. 0.0381 0.0330 0.0355
10:01-11:00, Mon., 18 Aug. 0.0384 0.0336 0.0359
09:01-10:00, Mon., 18 Aug. 0.0384 0.0343 0.0361
08:01-09:00, Mon., 18 Aug. 0.0385 0.0331 0.0359
07:01-08:00, Mon., 18 Aug. 0.0395 0.0346 0.0367
06:01-07:00, Mon., 18 Aug. 0.0406 0.0353 0.0377
05:01-06:00, Mon., 18 Aug. 0.0416 0.0362 0.0387
04:01-05:00, Mon., 18 Aug. 0.0421 0.0369 0.0394
03:01-04:00, Mon., 18 Aug. 0.0411 0.0359 0.0384
02:01-03:00, Mon., 18 Aug. 0.0401 0.0347 0.0380
01:01-02:00, Mon., 18 Aug. 0.0405 0.0356 0.0380
00:01-01:00, Mon., 18 Aug. 0.0404 0.0334 0.0371
23:01-24:00, Sun., 17 Aug. 0.0381 0.0336 0.0359
22:01-23:00, Sun., 17 Aug. 0.0378 0.0327 0.0352
21:01-22:00, Sun., 17 Aug. 0.0373 0.0320 0.0348
20:01-21:00, Sun., 17 Aug. 0.0374 0.0316 0.0346
19:01-20:00, Sun., 17 Aug. 0.0372 0.0325 0.0348
18:01-19:00, Sun., 17 Aug. 0.0363 0.0322 0.0347
17:01-18:00, Sun., 17 Aug. 0.0367 0.0319 0.0348
16:01-17:00, Sun., 17 Aug. 0.0365 0.0322 0.0343
15:01-16:00, Sun., 17 Aug. 0.0367 0.0322 0.0343
14:01-15:00, Sun., 17 Aug. 0.0370 0.0321 0.0343
13:01-14:00, Sun., 17 Aug. 0.0360 0.0318 0.0341
12:01-13:00, Sun., 17 Aug. 0.0360 0.0318 0.0343
11:01-12:00, Sun., 17 Aug. 0.0365 0.0317 0.0343
10:01-11:00, Sun., 17 Aug. 0.0387 0.0329 0.0349
09:01-10:00, Sun., 17 Aug. 0.0373 0.0315 0.0348
08:01-09:00, Sun., 17 Aug. 0.0377 0.0333 0.0356
07:01-08:00, Sun., 17 Aug. 0.0377 0.0345 0.0360
11:01-12:00, Sat., 16 Aug. 0.0371 0.0320 0.0339
10:01-11:00, Sat., 16 Aug. 0.0383 0.0325 0.0349
09:01-10:00, Sat., 16 Aug. 0.0383 0.0332 0.0355
08:01-09:00, Sat., 16 Aug. 0.0385 0.0341 0.0361
07:01-08:00, Sat., 16 Aug. 0.0396 0.0341 0.0370
06:01-07:00, Sat., 16 Aug. 0.0400 0.0343 0.0373
05:01-06:00, Sat., 16 Aug. 0.0390 0.0350 0.0372
04:01-05:00, Sat., 16 Aug. 0.0408 0.0356 0.0373
03:01-04:00, Sat., 16 Aug. 0.0389 0.0342 0.0367
02:01-03:00, Sat., 16 Aug. 0.0371 0.0321 0.0347
01:01-02:00, Sat., 16 Aug. 0.0377 0.0325 0.0345
00:01-01:00, Sat., 16 Aug. 0.0367 0.0297 0.0343
23:01-24:00, Fri., 15 Aug. 0.0359 0.0321 0.0343
22:01-23:00, Fri., 15 Aug. 0.0371 0.0311 0.0343
21:01-22:00, Fri., 15 Aug. 0.0370 0.0310 0.0340
20:01-21:00, Fri., 15 Aug. 0.0361 0.0325 0.0343
19:01-20:00, Fri., 15 Aug. 0.0364 0.0314 0.0342
18:01-19:00, Fri., 15 Aug. 0.0363 0.0318 0.0341
17:01-18:00, Fri., 15 Aug. 0.0363 0.0315 0.0339
16:01-17:00, Fri., 15 Aug. 0.0360 0.0315 0.0338
15:01-16:00, Fri., 15 Aug. 0.0360 0.0322 0.0341
14:01-15:00, Fri., 15 Aug. 0.0367 0.0319 0.0336
13:01-14:00, Fri., 15 Aug. 0.0370 0.0322 0.0340
12:01-13:00, Fri., 15 Aug. 0.0371 0.0322 0.0343
11:01-12:00, Fri., 15 Aug. 0.0369 0.0325 0.0344
10:01-11:00, Fri., 15 Aug. 0.0367 0.0331 0.0347
09:01-10:00, Fri., 15 Aug. 0.0374 0.0334 0.0350
08:01-09:00, Fri., 15 Aug. 0.0376 0.0335 0.0354
07:01-08:00, Fri., 15 Aug. 0.0377 0.0336 0.0358
06:01-07:00, Fri., 15 Aug. 0.0392 0.0325 0.0359
05:01-06:00, Fri., 15 Aug. 0.0378 0.0329 0.0355
04:01-05:00, Fri., 15 Aug. 0.0388 0.0332 0.0358
03:01-04:00, Fri., 15 Aug. 0.0368 0.0327 0.0349
02:01-03:00, Fri., 15 Aug. 0.0365 0.0322 0.0342
01:01-02:00, Fri., 15 Aug. 0.0364 0.0322 0.0339
00:01-01:00, Fri., 15 Aug. 0.0370 0.0315 0.0338
23:01-24:00, Thu., 14 Aug. 0.0367 0.0318 0.0340
22:01-23:00, Thu., 14 Aug. 0.0365 0.0315 0.0338
21:01-22:00, Thu., 14 Aug. 0.0370 0.0313 0.0343
20:01-21:00, Thu., 14 Aug. 0.0372 0.0312 0.0340
19:01-20:00, Thu., 14 Aug. 0.0372 0.0311 0.0338
18:01-19:00, Thu., 14 Aug. 0.0360 0.0317 0.0336
17:01-18:00, Thu., 14 Aug. 0.0363 0.0308 0.0338
16:01-17:00, Thu., 14 Aug. 0.0363 0.0314 0.0337
15:01-16:00, Thu., 14 Aug. 0.0363 0.0321 0.0343
14:01-15:00, Thu., 14 Aug. 0.0370 0.0320 0.0340
13:01-14:00, Thu., 14 Aug. 0.0360 0.0317 0.0339
12:01-13:00, Thu., 14 Aug. 0.0364 0.0314 0.0341
11:01-12:00, Thu., 14 Aug. 0.0363 0.0323 0.0342
10:01-11:00, Thu., 14 Aug. 0.0367 0.0323 0.0343
09:01-10:00, Thu., 14 Aug. 0.0377 0.0320 0.0341
08:01-09:00, Thu., 14 Aug. 0.0363 0.0318 0.0342
07:01-08:00, Thu., 14 Aug. 0.0369 0.0322 0.0344
06:01-07:00, Thu., 14 Aug. 0.0363 0.0315 0.0343
05:01-06:00, Thu., 14 Aug. 0.0373 0.0322 0.0343
04:01-05:00, Thu., 14 Aug. 0.0363 0.0318 0.0341
03:01-04:00, Thu., 14 Aug. 0.0368 0.0315 0.0345
02:01-03:00, Thu., 14 Aug. 0.0370 0.0323 0.0346
01:01-02:00, Thu., 14 Aug. 0.0363 0.0325 0.0344
00:01-01:00, Thu., 14 Aug. 0.0361 0.0318 0.0345
23:01-24:00, Wed., 13 Aug. 0.0371 0.0329 0.0347
22:01-23:00, Wed., 13 Aug. 0.0372 0.0324 0.0347
21:01-22:00, Wed., 13 Aug. 0.0370 0.0315 0.0344
20:01-21:00, Wed., 13 Aug. 0.0368 0.0322 0.0343
19:01-20:00, Wed., 13 Aug. 0.0367 0.0323 0.0342
18:01-19:00, Wed., 13 Aug. 0.0363 0.0314 0.0339
17:01-18:00, Wed., 13 Aug. 0.0364 0.0312 0.0339
16:01-17:00, Wed., 13 Aug. 0.0368 0.0318 0.0341
15:01-16:00, Wed., 13 Aug. 0.0370 0.0316 0.0342
14:01-15:00, Wed., 13 Aug. 0.0364 0.0323 0.0342
13:01-14:00, Wed., 13 Aug. 0.0369 0.0323 0.0342
12:01-13:00, Wed., 13 Aug. 0.0363 0.0328 0.0343
11:01-12:00, Wed., 13 Aug. 0.0360 0.0321 0.0341
10:01-11:00, Wed., 13 Aug. 0.0368 0.0322 0.0343
09:01-10:00, Wed., 13 Aug. 0.0373 0.0329 0.0350
08:01-09:00, Wed., 13 Aug. 0.0385 0.0323 0.0353
07:01-08:00, Wed., 13 Aug. 0.0391 0.0335 0.0355
06:01-07:00, Wed., 13 Aug. 0.0377 0.0329 0.0356
05:01-06:00, Wed., 13 Aug. 0.0370 0.0316 0.0347
04:01-05:00, Wed., 13 Aug. 0.0363 0.0311 0.0342
03:01-04:00, Wed., 13 Aug. 0.0365 0.0322 0.0345
02:01-03:00, Wed., 13 Aug. 0.0370 0.0330 0.0348
01:01-02:00, Wed., 13 Aug. 0.0398 0.0329 0.0363
00:01-01:00, Wed., 13 Aug. 0.0381 0.0334 0.0361
23:01-24:00, Tue., 12 Aug. 0.0389 0.0344 0.0363
22:01-23:00, Tue., 12 Aug. 0.0402 0.0338 0.0365
21:01-22:00, Tue., 12 Aug. 0.0408 0.0350 0.0374
20:01-21:00, Tue., 12 Aug. 0.0430 0.0367 0.0400
19:01-20:00, Tue., 12 Aug. 0.0452 0.0404 0.0429
18:01-19:00, Tue., 12 Aug. 0.0443 0.0395 0.0419
17:01-18:00, Tue., 12 Aug. 0.0434 0.0352 0.0391
16:01-17:00, Tue., 12 Aug. 0.0377 0.0333 0.0354
15:01-16:00, Tue., 12 Aug. 0.0374 0.0335 0.0354
14:01-15:00, Tue., 12 Aug. 0.0384 0.0327 0.0350
13:01-14:00, Tue., 12 Aug. 0.0375 0.0320 0.0346
12:01-13:00, Tue., 12 Aug. 0.0352 0.0309 0.0335
11:01-12:00, Tue., 12 Aug. 0.0369 0.0310 0.0336
10:01-11:00, Tue., 12 Aug. 0.0366 0.0310 0.0334
09:01-10:00, Tue., 12 Aug. 0.0356 0.0310 0.0334
08:01-09:00, Tue., 12 Aug. 0.0357 0.0304 0.0333
07:01-08:00, Tue., 12 Aug. 0.0360 0.0314 0.0335
06:01-07:00, Tue., 12 Aug. 0.0363 0.0315 0.0335
05:01-06:00, Tue., 12 Aug. 0.0369 0.0315 0.0336
04:01-05:00, Tue., 12 Aug. 0.0363 0.0311 0.0337
03:01-04:00, Tue., 12 Aug. 0.0360 0.0314 0.0335
02:01-03:00, Tue., 12 Aug. 0.0361 0.0316 0.0337
01:01-02:00, Tue., 12 Aug. 0.0376 0.0323 0.0347
00:01-01:00, Tue., 12 Aug. 0.0361 0.0315 0.0337
23:01-24:00, Mon., 11 Aug. 0.0357 0.0310 0.0337
22:01-23:00, Mon., 11 Aug. 0.0357 0.0310 0.0336
21:01-22:00, Mon., 11 Aug. 0.0362 0.0304 0.0333
20:01-21:00, Mon., 11 Aug. 0.0363 0.0307 0.0335
19:01-20:00, Mon., 11 Aug. 0.0374 0.0304 0.0333
18:01-19:00, Mon., 11 Aug. 0.0363 0.0315 0.0337
17:01-18:00, Mon., 11 Aug. 0.0374 0.0315 0.0348
16:01-17:00, Mon., 11 Aug. 0.0382 0.0332 0.0357
15:01-16:00, Mon., 11 Aug. 0.0364 0.0313 0.0339
14:01-15:00, Mon., 11 Aug. 0.0357 0.0304 0.0336
13:01-14:00, Mon., 11 Aug. 0.0367 0.0316 0.0341
12:01-13:00, Mon., 11 Aug. 0.0373 0.0313 0.0344
11:01-12:00, Mon., 11 Aug. 0.0370 0.0325 0.0344
10:01-11:00, Mon., 11 Aug. 0.0389 0.0334 0.0355
09:01-10:00, Mon., 11 Aug. 0.0413 0.0350 0.0379
08:01-09:00, Mon., 11 Aug. 0.0398 0.0336 0.0369
07:01-08:00, Mon., 11 Aug. 0.0349 0.0309 0.0332
06:01-07:00, Mon., 11 Aug. 0.0349 0.0311 0.0332
05:01-06:00, Mon., 11 Aug. 0.0364 0.0311 0.0332
04:01-05:00, Mon., 11 Aug. 0.0360 0.0312 0.0336
03:01-04:00, Mon., 11 Aug. 0.0378 0.0315 0.0342
02:01-03:00, Mon., 11 Aug. 0.0404 0.0341 0.0368
01:01-02:00, Mon., 11 Aug. 0.0432 0.0372 0.0402
00:01-01:00, Mon., 11 Aug. 0.0423 0.0352 0.0390
23:01-24:00, Sun., 10 Aug. 0.0447 0.0367 0.0412
22:01-23:00, Sun., 10 Aug. 0.0431 0.0368 0.0397
21:01-22:00, Sun., 10 Aug. 0.0430 0.0373 0.0400
20:01-21:00, Sun., 10 Aug. 0.0411 0.0342 0.0373
19:01-20:00, Sun., 10 Aug. 0.0380 0.0317 0.0358
18:01-19:00, Sun., 10 Aug. 0.0375 0.0332 0.0353
17:01-18:00, Sun., 10 Aug. 0.0375 0.0324 0.0351
16:01-17:00, Sun., 10 Aug. 0.0383 0.0332 0.0360
15:01-16:00, Sun., 10 Aug. 0.0404 0.0347 0.0376
14:01-15:00, Sun., 10 Aug. 0.0383 0.0333 0.0357
13:01-14:00, Sun., 10 Aug. 0.0384 0.0336 0.0356
12:01-13:00, Sun., 10 Aug. 0.0379 0.0329 0.0353
11:01-12:00, Sun., 10 Aug. 0.0391 0.0328 0.0355
10:01-11:00, Sun., 10 Aug. 0.0391 0.0346 0.0366
09:01-10:00, Sun., 10 Aug. 0.0407 0.0358 0.0382
08:01-09:00, Sun., 10 Aug. 0.0440 0.0368 0.0407
07:01-08:00, Sun., 10 Aug. 0.0416 0.0365 0.0390
06:01-07:00, Sun., 10 Aug. 0.0407 0.0360 0.0382
05:01-06:00, Sun., 10 Aug. 0.0409 0.0363 0.0390
04:01-05:00, Sun., 10 Aug. 0.0417 0.0367 0.0396
03:01-04:00, Sun., 10 Aug. 0.0414 0.0370 0.0390
02:01-03:00, Sun., 10 Aug. 0.0428 0.0360 0.0395
01:01-02:00, Sun., 10 Aug. 0.0398 0.0349 0.0373
00:01-01:00, Sun., 10 Aug. 0.0398 0.0352 0.0371
23:01-24:00, Sat., 09 Aug. 0.0397 0.0346 0.0367
22:01-23:00, Sat., 09 Aug. 0.0389 0.0346 0.0365
21:01-22:00, Sat., 09 Aug. 0.0399 0.0339 0.0363
20:01-21:00, Sat., 09 Aug. 0.0384 0.0328 0.0358
19:01-20:00, Sat., 09 Aug. 0.0373 0.0333 0.0358
18:01-19:00, Sat., 09 Aug. 0.0382 0.0336 0.0357
17:01-18:00, Sat., 09 Aug. 0.0391 0.0339 0.0359
16:01-17:00, Sat., 09 Aug. 0.0387 0.0339 0.0363
15:01-16:00, Sat., 09 Aug. 0.0384 0.0339 0.0361
14:01-15:00, Sat., 09 Aug. 0.0388 0.0332 0.0363
13:01-14:00, Sat., 09 Aug. 0.0384 0.0339 0.0360
12:01-13:00, Sat., 09 Aug. 0.0388 0.0336 0.0362
11:01-12:00, Sat., 09 Aug. 0.0387 0.0331 0.0358
10:01-11:00, Sat., 09 Aug. 0.0395 0.0330 0.0362
09:01-10:00, Sat., 09 Aug. 0.0384 0.0337 0.0362
08:01-09:00, Sat., 09 Aug. 0.0394 0.0352 0.0366
07:01-08:00, Sat., 09 Aug. 0.0403 0.0356 0.0379
06:01-07:00, Sat., 09 Aug. 0.0405 0.0358 0.0381
05:01-06:00, Sat., 09 Aug. 0.0402 0.0357 0.0379
04:01-05:00, Sat., 09 Aug. 0.0398 0.0355 0.0378
03:01-04:00, Sat., 09 Aug. 0.0397 0.0352 0.0377
02:01-03:00, Sat., 09 Aug. 0.0407 0.0344 0.0372
01:01-02:00, Sat., 09 Aug. 0.0406 0.0346 0.0367
00:01-01:00, Sat., 09 Aug. 0.0391 0.0343 0.0366
23:01-24:00, Fri., 08 Aug. 0.0388 0.0346 0.0365
22:01-23:00, Fri., 08 Aug. 0.0380 0.0341 0.0364
21:01-22:00, Fri., 08 Aug. 0.0387 0.0346 0.0363
20:01-21:00, Fri., 08 Aug. 0.0393 0.0329 0.0364
19:01-20:00, Fri., 08 Aug. 0.0394 0.0333 0.0368
18:01-19:00, Fri., 08 Aug. 0.0395 0.0344 0.0367
17:01-18:00, Fri., 08 Aug. 0.0409 0.0349 0.0379
16:01-17:00, Fri., 08 Aug. 0.0442 0.0369 0.0400
15:01-16:00, Fri., 08 Aug. 0.0443 0.0353 0.0391
14:01-15:00, Fri., 08 Aug. 0.0405 0.0348 0.0376
13:01-14:00, Fri., 08 Aug. 0.0390 0.0318 0.0361
12:01-13:00, Fri., 08 Aug. 0.0388 0.0336 0.0361
11:01-12:00, Fri., 08 Aug. 0.0391 0.0343 0.0365
10:01-11:00, Fri., 08 Aug. 0.0396 0.0335 0.0367
09:01-10:00, Fri., 08 Aug. 0.0405 0.0349 0.0368
08:01-09:00, Fri., 08 Aug. 0.0406 0.0353 0.0370
07:01-08:00, Fri., 08 Aug. 0.0399 0.0351 0.0376
06:01-07:00, Fri., 08 Aug. 0.0416 0.0360 0.0385
05:01-06:00, Fri., 08 Aug. 0.0409 0.0363 0.0382
04:01-05:00, Fri., 08 Aug. 0.0417 0.0359 0.0387
03:01-04:00, Fri., 08 Aug. 0.0415 0.0361 0.0388
02:01-03:00, Fri., 08 Aug. 0.0408 0.0352 0.0380
01:01-02:00, Fri., 08 Aug. 0.0399 0.0348 0.0379
00:01-01:00, Fri., 08 Aug. 0.0409 0.0361 0.0381
23:01-24:00, Thu., 07 Aug. 0.0401 0.0360 0.0378
22:01-23:00, Thu., 07 Aug. 0.0391 0.0339 0.0369