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
04:01-05:00, Fri., 21 Nov. 0.0379 0.0326 0.0351
03:01-04:00, Fri., 21 Nov. 0.0368 0.0327 0.0350
02:01-03:00, Fri., 21 Nov. 0.0374 0.0326 0.0350
01:01-02:00, Fri., 21 Nov. 0.0372 0.0329 0.0350
00:01-01:00, Fri., 21 Nov. 0.0374 0.0311 0.0349
23:01-24:00, Thu., 20 Nov. 0.0381 0.0331 0.0348
22:01-23:00, Thu., 20 Nov. 0.0370 0.0327 0.0349
21:01-22:00, Thu., 20 Nov. 0.0372 0.0315 0.0347
20:01-21:00, Thu., 20 Nov. 0.0368 0.0327 0.0347
19:01-20:00, Thu., 20 Nov. 0.0366 0.0324 0.0345
18:01-19:00, Thu., 20 Nov. 0.0370 0.0320 0.0341
17:01-18:00, Thu., 20 Nov. 0.0361 0.0308 0.0339
16:01-17:00, Thu., 20 Nov. 0.0367 0.0317 0.0338
15:01-16:00, Thu., 20 Nov. 0.0363 0.0310 0.0339
14:01-15:00, Thu., 20 Nov. 0.0372 0.0315 0.0341
13:01-14:00, Thu., 20 Nov. 0.0366 0.0311 0.0341
12:01-13:00, Thu., 20 Nov. 0.0373 0.0325 0.0347
11:01-12:00, Thu., 20 Nov. 0.0376 0.0329 0.0349
10:01-11:00, Thu., 20 Nov. 0.0383 0.0332 0.0354
09:01-10:00, Thu., 20 Nov. 0.0374 0.0327 0.0350
08:01-09:00, Thu., 20 Nov. 0.0388 0.0337 0.0363
07:01-08:00, Thu., 20 Nov. 0.0395 0.0344 0.0365
06:01-07:00, Thu., 20 Nov. 0.0388 0.0343 0.0372
05:01-06:00, Thu., 20 Nov. 0.0395 0.0339 0.0371
04:01-05:00, Thu., 20 Nov. 0.0391 0.0342 0.0366
03:01-04:00, Thu., 20 Nov. 0.0395 0.0339 0.0365
02:01-03:00, Thu., 20 Nov. 0.0393 0.0339 0.0362
01:01-02:00, Thu., 20 Nov. 0.0396 0.0336 0.0360
00:01-01:00, Thu., 20 Nov. 0.0376 0.0324 0.0356
23:01-24:00, Wed., 19 Nov. 0.0378 0.0336 0.0354
22:01-23:00, Wed., 19 Nov. 0.0368 0.0327 0.0349
21:01-22:00, Wed., 19 Nov. 0.0370 0.0336 0.0352
20:01-21:00, Wed., 19 Nov. 0.0376 0.0320 0.0349
19:01-20:00, Wed., 19 Nov. 0.0374 0.0329 0.0347
18:01-19:00, Wed., 19 Nov. 0.0367 0.0316 0.0344
17:01-18:00, Wed., 19 Nov. 0.0365 0.0320 0.0342
16:01-17:00, Wed., 19 Nov. 0.0367 0.0318 0.0340
15:01-16:00, Wed., 19 Nov. 0.0371 0.0308 0.0346
14:01-15:00, Wed., 19 Nov. 0.0360 0.0316 0.0343
13:01-14:00, Wed., 19 Nov. 0.0365 0.0308 0.0340
12:01-13:00, Wed., 19 Nov. 0.0375 0.0318 0.0344
11:01-12:00, Wed., 19 Nov. 0.0365 0.0318 0.0342
10:01-11:00, Wed., 19 Nov. 0.0363 0.0322 0.0345
09:01-10:00, Wed., 19 Nov. 0.0380 0.0333 0.0356
08:01-09:00, Wed., 19 Nov. 0.0383 0.0337 0.0358
07:01-08:00, Wed., 19 Nov. 0.0383 0.0330 0.0352
06:01-07:00, Wed., 19 Nov. 0.0371 0.0325 0.0350
05:01-06:00, Wed., 19 Nov. 0.0376 0.0332 0.0356
04:01-05:00, Wed., 19 Nov. 0.0373 0.0326 0.0349
03:01-04:00, Wed., 19 Nov. 0.0374 0.0322 0.0345
02:01-03:00, Wed., 19 Nov. 0.0370 0.0328 0.0350
01:01-02:00, Wed., 19 Nov. 0.0373 0.0324 0.0351
00:01-01:00, Wed., 19 Nov. 0.0373 0.0327 0.0349
23:01-24:00, Tue., 18 Nov. 0.0363 0.0325 0.0347
22:01-23:00, Tue., 18 Nov. 0.0371 0.0325 0.0348
21:01-22:00, Tue., 18 Nov. 0.0376 0.0325 0.0346
20:01-21:00, Tue., 18 Nov. 0.0369 0.0325 0.0347
19:01-20:00, Tue., 18 Nov. 0.0374 0.0323 0.0347
18:01-19:00, Tue., 18 Nov. 0.0380 0.0329 0.0352
17:01-18:00, Tue., 18 Nov. 0.0381 0.0328 0.0352
16:01-17:00, Tue., 18 Nov. 0.0374 0.0325 0.0348
15:01-16:00, Tue., 18 Nov. 0.0379 0.0325 0.0346
14:01-15:00, Tue., 18 Nov. 0.0367 0.0330 0.0347
13:01-14:00, Tue., 18 Nov. 0.0377 0.0319 0.0347
12:01-13:00, Tue., 18 Nov. 0.0381 0.0328 0.0348
11:01-12:00, Tue., 18 Nov. 0.0378 0.0318 0.0350
10:01-11:00, Tue., 18 Nov. 0.0373 0.0330 0.0350
09:01-10:00, Tue., 18 Nov. 0.0376 0.0325 0.0346
08:01-09:00, Tue., 18 Nov. 0.0368 0.0327 0.0346
07:01-08:00, Tue., 18 Nov. 0.0363 0.0317 0.0344
06:01-07:00, Tue., 18 Nov. 0.0363 0.0322 0.0343
05:01-06:00, Tue., 18 Nov. 0.0366 0.0314 0.0343
04:01-05:00, Tue., 18 Nov. 0.0367 0.0318 0.0344
03:01-04:00, Tue., 18 Nov. 0.0370 0.0320 0.0344
02:01-03:00, Tue., 18 Nov. 0.0369 0.0315 0.0344
01:01-02:00, Tue., 18 Nov. 0.0369 0.0320 0.0345
00:01-01:00, Tue., 18 Nov. 0.0367 0.0318 0.0339
23:01-24:00, Mon., 17 Nov. 0.0364 0.0316 0.0341
22:01-23:00, Mon., 17 Nov. 0.0367 0.0313 0.0342
21:01-22:00, Mon., 17 Nov. 0.0377 0.0318 0.0339
20:01-21:00, Mon., 17 Nov. 0.0367 0.0315 0.0340
19:01-20:00, Mon., 17 Nov. 0.0363 0.0322 0.0341
18:01-19:00, Mon., 17 Nov. 0.0369 0.0322 0.0340
17:01-18:00, Mon., 17 Nov. 0.0370 0.0322 0.0341
16:01-17:00, Mon., 17 Nov. 0.0367 0.0317 0.0340
15:01-16:00, Mon., 17 Nov. 0.0366 0.0321 0.0343
14:01-15:00, Mon., 17 Nov. 0.0371 0.0316 0.0344
13:01-14:00, Mon., 17 Nov. 0.0364 0.0321 0.0342
12:01-13:00, Mon., 17 Nov. 0.0366 0.0315 0.0342
11:01-12:00, Mon., 17 Nov. 0.0374 0.0311 0.0339
10:01-11:00, Mon., 17 Nov. 0.0353 0.0309 0.0334
09:01-10:00, Mon., 17 Nov. 0.0363 0.0316 0.0340
08:01-09:00, Mon., 17 Nov. 0.0373 0.0297 0.0341
07:01-08:00, Mon., 17 Nov. 0.0374 0.0315 0.0343
06:01-07:00, Mon., 17 Nov. 0.0366 0.0311 0.0343
05:01-06:00, Mon., 17 Nov. 0.0370 0.0313 0.0344
04:01-05:00, Mon., 17 Nov. 0.0370 0.0312 0.0344
03:01-04:00, Mon., 17 Nov. 0.0373 0.0318 0.0344
02:01-03:00, Mon., 17 Nov. 0.0366 0.0325 0.0348
01:01-02:00, Mon., 17 Nov. 0.0364 0.0323 0.0343
00:01-01:00, Mon., 17 Nov. 0.0372 0.0319 0.0344
23:01-24:00, Sun., 16 Nov. 0.0354 0.0320 0.0338
22:01-23:00, Sun., 16 Nov. 0.0366 0.0314 0.0337
21:01-22:00, Sun., 16 Nov. 0.0360 0.0311 0.0339
20:01-21:00, Sun., 16 Nov. 0.0367 0.0315 0.0338
19:01-20:00, Sun., 16 Nov. 0.0362 0.0311 0.0336
18:01-19:00, Sun., 16 Nov. 0.0358 0.0314 0.0332
17:01-18:00, Sun., 16 Nov. 0.0365 0.0317 0.0338
16:01-17:00, Sun., 16 Nov. 0.0364 0.0310 0.0338
15:01-16:00, Sun., 16 Nov. 0.0362 0.0311 0.0334
14:01-15:00, Sun., 16 Nov. 0.0363 0.0314 0.0336
13:01-14:00, Sun., 16 Nov. 0.0363 0.0311 0.0339
12:01-13:00, Sun., 16 Nov. 0.0360 0.0320 0.0340
11:01-12:00, Sun., 16 Nov. 0.0365 0.0315 0.0338
10:01-11:00, Sun., 16 Nov. 0.0367 0.0315 0.0341
09:01-10:00, Sun., 16 Nov. 0.0372 0.0322 0.0349
08:01-09:00, Sun., 16 Nov. 0.0371 0.0319 0.0346
07:01-08:00, Sun., 16 Nov. 0.0375 0.0326 0.0346
06:01-07:00, Sun., 16 Nov. 0.0380 0.0324 0.0350
05:01-06:00, Sun., 16 Nov. 0.0375 0.0321 0.0348
04:01-05:00, Sun., 16 Nov. 0.0370 0.0328 0.0349
03:01-04:00, Sun., 16 Nov. 0.0370 0.0323 0.0349
02:01-03:00, Sun., 16 Nov. 0.0372 0.0333 0.0353
01:01-02:00, Sun., 16 Nov. 0.0375 0.0321 0.0346
00:01-01:00, Sun., 16 Nov. 0.0374 0.0329 0.0349
23:01-24:00, Sat., 15 Nov. 0.0376 0.0311 0.0343
22:01-23:00, Sat., 15 Nov. 0.0360 0.0308 0.0340
21:01-22:00, Sat., 15 Nov. 0.0359 0.0313 0.0335
20:01-21:00, Sat., 15 Nov. 0.0351 0.0316 0.0334
19:01-20:00, Sat., 15 Nov. 0.0353 0.0320 0.0335
18:01-19:00, Sat., 15 Nov. 0.0360 0.0315 0.0336
17:01-18:00, Sat., 15 Nov. 0.0363 0.0302 0.0336
16:01-17:00, Sat., 15 Nov. 0.0369 0.0320 0.0342
15:01-16:00, Sat., 15 Nov. 0.0360 0.0314 0.0339
14:01-15:00, Sat., 15 Nov. 0.0363 0.0322 0.0342
13:01-14:00, Sat., 15 Nov. 0.0360 0.0316 0.0337
12:01-13:00, Sat., 15 Nov. 0.0357 0.0311 0.0334
11:01-12:00, Sat., 15 Nov. 0.0364 0.0317 0.0336
10:01-11:00, Sat., 15 Nov. 0.0358 0.0316 0.0337
09:01-10:00, Sat., 15 Nov. 0.0361 0.0322 0.0339
08:01-09:00, Sat., 15 Nov. 0.0362 0.0322 0.0344
07:01-08:00, Sat., 15 Nov. 0.0360 0.0315 0.0342
06:01-07:00, Sat., 15 Nov. 0.0366 0.0324 0.0342
05:01-06:00, Sat., 15 Nov. 0.0367 0.0318 0.0345
04:01-05:00, Sat., 15 Nov. 0.0378 0.0315 0.0347
03:01-04:00, Sat., 15 Nov. 0.0369 0.0315 0.0343
02:01-03:00, Sat., 15 Nov. 0.0376 0.0318 0.0342
01:01-02:00, Sat., 15 Nov. 0.0362 0.0317 0.0339
00:01-01:00, Sat., 15 Nov. 0.0360 0.0318 0.0338
23:01-24:00, Fri., 14 Nov. 0.0358 0.0319 0.0340
22:01-23:00, Fri., 14 Nov. 0.0360 0.0316 0.0340
21:01-22:00, Fri., 14 Nov. 0.0357 0.0316 0.0338
20:01-21:00, Fri., 14 Nov. 0.0360 0.0310 0.0333
19:01-20:00, Fri., 14 Nov. 0.0360 0.0317 0.0339
18:01-19:00, Fri., 14 Nov. 0.0363 0.0319 0.0338
17:01-18:00, Fri., 14 Nov. 0.0355 0.0317 0.0337
16:01-17:00, Fri., 14 Nov. 0.0367 0.0320 0.0339
15:01-16:00, Fri., 14 Nov. 0.0367 0.0315 0.0341
14:01-15:00, Fri., 14 Nov. 0.0374 0.0331 0.0346
13:01-14:00, Fri., 14 Nov. 0.0360 0.0317 0.0341
12:01-13:00, Fri., 14 Nov. 0.0364 0.0315 0.0343
11:01-12:00, Fri., 14 Nov. 0.0363 0.0315 0.0342
10:01-11:00, Fri., 14 Nov. 0.0370 0.0321 0.0343
09:01-10:00, Fri., 14 Nov. 0.0366 0.0325 0.0346
08:01-09:00, Fri., 14 Nov. 0.0368 0.0329 0.0345
07:01-08:00, Fri., 14 Nov. 0.0373 0.0326 0.0348
06:01-07:00, Fri., 14 Nov. 0.0376 0.0319 0.0345
05:01-06:00, Fri., 14 Nov. 0.0369 0.0325 0.0343
04:01-05:00, Fri., 14 Nov. 0.0364 0.0324 0.0345
03:01-04:00, Fri., 14 Nov. 0.0364 0.0320 0.0344
02:01-03:00, Fri., 14 Nov. 0.0373 0.0317 0.0346
01:01-02:00, Fri., 14 Nov. 0.0367 0.0319 0.0343
00:01-01:00, Fri., 14 Nov. 0.0377 0.0321 0.0346
23:01-24:00, Thu., 13 Nov. 0.0372 0.0324 0.0347
22:01-23:00, Thu., 13 Nov. 0.0374 0.0336 0.0354
21:01-22:00, Thu., 13 Nov. 0.0377 0.0331 0.0354
20:01-21:00, Thu., 13 Nov. 0.0375 0.0337 0.0354
19:01-20:00, Thu., 13 Nov. 0.0380 0.0331 0.0357
18:01-19:00, Thu., 13 Nov. 0.0387 0.0332 0.0357
17:01-18:00, Thu., 13 Nov. 0.0377 0.0323 0.0350
16:01-17:00, Thu., 13 Nov. 0.0384 0.0331 0.0349
15:01-16:00, Thu., 13 Nov. 0.0370 0.0328 0.0349
14:01-15:00, Thu., 13 Nov. 0.0374 0.0324 0.0349
13:01-14:00, Thu., 13 Nov. 0.0375 0.0327 0.0348
12:01-13:00, Thu., 13 Nov. 0.0384 0.0335 0.0357
11:01-12:00, Thu., 13 Nov. 0.0393 0.0336 0.0359
10:01-11:00, Thu., 13 Nov. 0.0398 0.0331 0.0364
09:01-10:00, Thu., 13 Nov. 0.0402 0.0351 0.0370
08:01-09:00, Thu., 13 Nov. 0.0395 0.0345 0.0370
07:01-08:00, Thu., 13 Nov. 0.0385 0.0330 0.0358
06:01-07:00, Thu., 13 Nov. 0.0375 0.0334 0.0355
05:01-06:00, Thu., 13 Nov. 0.0374 0.0336 0.0355
04:01-05:00, Thu., 13 Nov. 0.0383 0.0336 0.0356
03:01-04:00, Thu., 13 Nov. 0.0377 0.0335 0.0356
02:01-03:00, Thu., 13 Nov. 0.0381 0.0333 0.0360
01:01-02:00, Thu., 13 Nov. 0.0381 0.0335 0.0355
00:01-01:00, Thu., 13 Nov. 0.0383 0.0327 0.0352
23:01-24:00, Wed., 12 Nov. 0.0363 0.0327 0.0343
22:01-23:00, Wed., 12 Nov. 0.0365 0.0314 0.0341
21:01-22:00, Wed., 12 Nov. 0.0360 0.0314 0.0341
20:01-21:00, Wed., 12 Nov. 0.0364 0.0305 0.0339
19:01-20:00, Wed., 12 Nov. 0.0363 0.0314 0.0338
18:01-19:00, Wed., 12 Nov. 0.0363 0.0317 0.0334
17:01-18:00, Wed., 12 Nov. 0.0363 0.0309 0.0334
16:01-17:00, Wed., 12 Nov. 0.0357 0.0309 0.0333
15:01-16:00, Wed., 12 Nov. 0.0360 0.0302 0.0333
14:01-15:00, Wed., 12 Nov. 0.0362 0.0301 0.0334
13:01-14:00, Wed., 12 Nov. 0.0360 0.0315 0.0335
12:01-13:00, Wed., 12 Nov. 0.0354 0.0309 0.0333
11:01-12:00, Wed., 12 Nov. 0.0374 0.0304 0.0335
10:01-11:00, Wed., 12 Nov. 0.0363 0.0297 0.0336
09:01-10:00, Wed., 12 Nov. 0.0374 0.0317 0.0340
08:01-09:00, Wed., 12 Nov. 0.0373 0.0325 0.0346
07:01-08:00, Wed., 12 Nov. 0.0367 0.0329 0.0350
06:01-07:00, Wed., 12 Nov. 0.0380 0.0317 0.0347
05:01-06:00, Wed., 12 Nov. 0.0367 0.0331 0.0349
04:01-05:00, Wed., 12 Nov. 0.0374 0.0323 0.0350
03:01-04:00, Wed., 12 Nov. 0.0368 0.0315 0.0347
02:01-03:00, Wed., 12 Nov. 0.0364 0.0323 0.0345
01:01-02:00, Wed., 12 Nov. 0.0366 0.0317 0.0339
00:01-01:00, Wed., 12 Nov. 0.0386 0.0319 0.0340
23:01-24:00, Tue., 11 Nov. 0.0365 0.0316 0.0336
22:01-23:00, Tue., 11 Nov. 0.0357 0.0319 0.0339
21:01-22:00, Tue., 11 Nov. 0.0356 0.0315 0.0339
20:01-21:00, Tue., 11 Nov. 0.0363 0.0309 0.0336
19:01-20:00, Tue., 11 Nov. 0.0353 0.0314 0.0334
18:01-19:00, Tue., 11 Nov. 0.0358 0.0312 0.0336
17:01-18:00, Tue., 11 Nov. 0.0353 0.0312 0.0333
16:01-17:00, Tue., 11 Nov. 0.0356 0.0302 0.0335
15:01-16:00, Tue., 11 Nov. 0.0363 0.0312 0.0337
14:01-15:00, Tue., 11 Nov. 0.0364 0.0322 0.0341
13:01-14:00, Tue., 11 Nov. 0.0368 0.0310 0.0340
12:01-13:00, Tue., 11 Nov. 0.0362 0.0304 0.0339
11:01-12:00, Tue., 11 Nov. 0.0367 0.0327 0.0344
10:01-11:00, Tue., 11 Nov. 0.0367 0.0315 0.0344
09:01-10:00, Tue., 11 Nov. 0.0381 0.0325 0.0352
08:01-09:00, Tue., 11 Nov. 0.0376 0.0325 0.0352
07:01-08:00, Tue., 11 Nov. 0.0380 0.0330 0.0354
06:01-07:00, Tue., 11 Nov. 0.0381 0.0329 0.0350
05:01-06:00, Tue., 11 Nov. 0.0371 0.0319 0.0350