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

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.

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
21:01-22:00, Sat., 11 Oct. 0.0380 0.0323 0.0348
20:01-21:00, Sat., 11 Oct. 0.0383 0.0340 0.0360
19:01-20:00, Sat., 11 Oct. 0.0398 0.0337 0.0370
18:01-19:00, Sat., 11 Oct. 0.0399 0.0353 0.0375
17:01-18:00, Sat., 11 Oct. 0.0415 0.0370 0.0393
16:01-17:00, Sat., 11 Oct. 0.0422 0.0352 0.0389
15:01-16:00, Sat., 11 Oct. 0.0426 0.0362 0.0392
14:01-15:00, Sat., 11 Oct. 0.0468 0.0404 0.0436
13:01-14:00, Sat., 11 Oct. 0.0453 0.0398 0.0430
12:01-13:00, Sat., 11 Oct. 0.0478 0.0420 0.0445
11:01-12:00, Sat., 11 Oct. 0.0509 0.0429 0.0472
10:01-11:00, Sat., 11 Oct. 0.0462 0.0393 0.0425
09:01-10:00, Sat., 11 Oct. 0.0424 0.0370 0.0396
08:01-09:00, Sat., 11 Oct. 0.0414 0.0360 0.0389
07:01-08:00, Sat., 11 Oct. 0.0426 0.0359 0.0388
06:01-07:00, Sat., 11 Oct. 0.0405 0.0337 0.0376
05:01-06:00, Sat., 11 Oct. 0.0392 0.0334 0.0372
04:01-05:00, Sat., 11 Oct. 0.0401 0.0348 0.0377
03:01-04:00, Sat., 11 Oct. 0.0426 0.0365 0.0389
02:01-03:00, Sat., 11 Oct. 0.0398 0.0344 0.0372
01:01-02:00, Sat., 11 Oct. 0.0385 0.0340 0.0363
00:01-01:00, Sat., 11 Oct. 0.0380 0.0331 0.0359
23:01-24:00, Fri., 10 Oct. 0.0383 0.0332 0.0355
22:01-23:00, Fri., 10 Oct. 0.0388 0.0325 0.0349
21:01-22:00, Fri., 10 Oct. 0.0380 0.0325 0.0350
20:01-21:00, Fri., 10 Oct. 0.0374 0.0330 0.0350
19:01-20:00, Fri., 10 Oct. 0.0371 0.0331 0.0349
18:01-19:00, Fri., 10 Oct. 0.0376 0.0330 0.0350
17:01-18:00, Fri., 10 Oct. 0.0371 0.0324 0.0350
16:01-17:00, Fri., 10 Oct. 0.0374 0.0327 0.0351
15:01-16:00, Fri., 10 Oct. 0.0365 0.0329 0.0348
14:01-15:00, Fri., 10 Oct. 0.0380 0.0326 0.0348
13:01-14:00, Fri., 10 Oct. 0.0377 0.0325 0.0350
12:01-13:00, Fri., 10 Oct. 0.0374 0.0328 0.0354
11:01-12:00, Fri., 10 Oct. 0.0373 0.0321 0.0349
10:01-11:00, Fri., 10 Oct. 0.0376 0.0329 0.0352
09:01-10:00, Fri., 10 Oct. 0.0370 0.0327 0.0350
08:01-09:00, Fri., 10 Oct. 0.0377 0.0332 0.0353
07:01-08:00, Fri., 10 Oct. 0.0378 0.0329 0.0353
06:01-07:00, Fri., 10 Oct. 0.0377 0.0325 0.0352
05:01-06:00, Fri., 10 Oct. 0.0366 0.0330 0.0350
04:01-05:00, Fri., 10 Oct. 0.0366 0.0323 0.0348
03:01-04:00, Fri., 10 Oct. 0.0380 0.0322 0.0351
02:01-03:00, Fri., 10 Oct. 0.0371 0.0327 0.0348
01:01-02:00, Fri., 10 Oct. 0.0366 0.0318 0.0347
00:01-01:00, Fri., 10 Oct. 0.0384 0.0323 0.0349
23:01-24:00, Thu., 09 Oct. 0.0381 0.0325 0.0350
22:01-23:00, Thu., 09 Oct. 0.0375 0.0328 0.0349
21:01-22:00, Thu., 09 Oct. 0.0368 0.0330 0.0349
20:01-21:00, Thu., 09 Oct. 0.0374 0.0330 0.0351
19:01-20:00, Thu., 09 Oct. 0.0386 0.0322 0.0351
18:01-19:00, Thu., 09 Oct. 0.0379 0.0328 0.0352
17:01-18:00, Thu., 09 Oct. 0.0378 0.0324 0.0350
16:01-17:00, Thu., 09 Oct. 0.0372 0.0329 0.0351
15:01-16:00, Thu., 09 Oct. 0.0381 0.0333 0.0353
14:01-15:00, Thu., 09 Oct. 0.0372 0.0330 0.0353
13:01-14:00, Thu., 09 Oct. 0.0377 0.0322 0.0352
12:01-13:00, Thu., 09 Oct. 0.0368 0.0333 0.0350
11:01-12:00, Thu., 09 Oct. 0.0388 0.0324 0.0351
10:01-11:00, Thu., 09 Oct. 0.0379 0.0327 0.0353
09:01-10:00, Thu., 09 Oct. 0.0384 0.0329 0.0357
08:01-09:00, Thu., 09 Oct. 0.0382 0.0331 0.0352
07:01-08:00, Thu., 09 Oct. 0.0383 0.0338 0.0358
06:01-07:00, Thu., 09 Oct. 0.0371 0.0336 0.0355
05:01-06:00, Thu., 09 Oct. 0.0377 0.0322 0.0351
04:01-05:00, Thu., 09 Oct. 0.0376 0.0329 0.0352
03:01-04:00, Thu., 09 Oct. 0.0375 0.0326 0.0351
02:01-03:00, Thu., 09 Oct. 0.0380 0.0329 0.0356
01:01-02:00, Thu., 09 Oct. 0.0380 0.0327 0.0353
00:01-01:00, Thu., 09 Oct. 0.0378 0.0326 0.0354
23:01-24:00, Wed., 08 Oct. 0.0377 0.0326 0.0356
22:01-23:00, Wed., 08 Oct. 0.0380 0.0327 0.0353
21:01-22:00, Wed., 08 Oct. 0.0373 0.0335 0.0352
20:01-21:00, Wed., 08 Oct. 0.0372 0.0334 0.0351
19:01-20:00, Wed., 08 Oct. 0.0375 0.0322 0.0347
18:01-19:00, Wed., 08 Oct. 0.0369 0.0317 0.0342
17:01-18:00, Wed., 08 Oct. 0.0365 0.0320 0.0342
16:01-17:00, Wed., 08 Oct. 0.0375 0.0320 0.0345
15:01-16:00, Wed., 08 Oct. 0.0368 0.0318 0.0345
14:01-15:00, Wed., 08 Oct. 0.0370 0.0325 0.0348
13:01-14:00, Wed., 08 Oct. 0.0368 0.0318 0.0347
12:01-13:00, Wed., 08 Oct. 0.0370 0.0325 0.0346
11:01-12:00, Wed., 08 Oct. 0.0361 0.0316 0.0343
10:01-11:00, Wed., 08 Oct. 0.0367 0.0315 0.0345
09:01-10:00, Wed., 08 Oct. 0.0370 0.0320 0.0347
08:01-09:00, Wed., 08 Oct. 0.0370 0.0325 0.0348
07:01-08:00, Wed., 08 Oct. 0.0383 0.0323 0.0353
06:01-07:00, Wed., 08 Oct. 0.0368 0.0325 0.0349
05:01-06:00, Wed., 08 Oct. 0.0374 0.0320 0.0347
04:01-05:00, Wed., 08 Oct. 0.0369 0.0327 0.0348
03:01-04:00, Wed., 08 Oct. 0.0367 0.0321 0.0348
02:01-03:00, Wed., 08 Oct. 0.0369 0.0313 0.0348
01:01-02:00, Wed., 08 Oct. 0.0382 0.0326 0.0351
00:01-01:00, Wed., 08 Oct. 0.0369 0.0329 0.0350
23:01-24:00, Tue., 07 Oct. 0.0376 0.0324 0.0347
22:01-23:00, Tue., 07 Oct. 0.0372 0.0329 0.0349
21:01-22:00, Tue., 07 Oct. 0.0365 0.0315 0.0349
20:01-21:00, Tue., 07 Oct. 0.0374 0.0326 0.0348
19:01-20:00, Tue., 07 Oct. 0.0373 0.0321 0.0344
18:01-19:00, Tue., 07 Oct. 0.0376 0.0317 0.0343
17:01-18:00, Tue., 07 Oct. 0.0371 0.0325 0.0345
16:01-17:00, Tue., 07 Oct. 0.0370 0.0322 0.0344
15:01-16:00, Tue., 07 Oct. 0.0363 0.0323 0.0343
14:01-15:00, Tue., 07 Oct. 0.0363 0.0320 0.0343
13:01-14:00, Tue., 07 Oct. 0.0367 0.0315 0.0342
12:01-13:00, Tue., 07 Oct. 0.0370 0.0317 0.0345
11:01-12:00, Tue., 07 Oct. 0.0371 0.0319 0.0345
10:01-11:00, Tue., 07 Oct. 0.0363 0.0322 0.0343
09:01-10:00, Tue., 07 Oct. 0.0364 0.0317 0.0343
08:01-09:00, Tue., 07 Oct. 0.0367 0.0324 0.0347
07:01-08:00, Tue., 07 Oct. 0.0364 0.0324 0.0346
06:01-07:00, Tue., 07 Oct. 0.0373 0.0325 0.0345
05:01-06:00, Tue., 07 Oct. 0.0370 0.0316 0.0345
04:01-05:00, Tue., 07 Oct. 0.0366 0.0322 0.0344
03:01-04:00, Tue., 07 Oct. 0.0374 0.0317 0.0344
02:01-03:00, Tue., 07 Oct. 0.0366 0.0324 0.0346
01:01-02:00, Tue., 07 Oct. 0.0370 0.0320 0.0344
00:01-01:00, Tue., 07 Oct. 0.0367 0.0322 0.0348
23:01-24:00, Mon., 06 Oct. 0.0377 0.0314 0.0350
22:01-23:00, Mon., 06 Oct. 0.0374 0.0326 0.0350
21:01-22:00, Mon., 06 Oct. 0.0369 0.0316 0.0343
20:01-21:00, Mon., 06 Oct. 0.0370 0.0320 0.0346
19:01-20:00, Mon., 06 Oct. 0.0367 0.0315 0.0340
18:01-19:00, Mon., 06 Oct. 0.0360 0.0319 0.0341
17:01-18:00, Mon., 06 Oct. 0.0365 0.0321 0.0343
16:01-17:00, Mon., 06 Oct. 0.0370 0.0320 0.0344
15:01-16:00, Mon., 06 Oct. 0.0377 0.0319 0.0350
14:01-15:00, Mon., 06 Oct. 0.0384 0.0318 0.0348
13:01-14:00, Mon., 06 Oct. 0.0374 0.0318 0.0346
12:01-13:00, Mon., 06 Oct. 0.0368 0.0325 0.0347
11:01-12:00, Mon., 06 Oct. 0.0377 0.0332 0.0353
10:01-11:00, Mon., 06 Oct. 0.0379 0.0337 0.0357
09:01-10:00, Mon., 06 Oct. 0.0381 0.0338 0.0356
08:01-09:00, Mon., 06 Oct. 0.0374 0.0316 0.0352
07:01-08:00, Mon., 06 Oct. 0.0371 0.0330 0.0354
06:01-07:00, Mon., 06 Oct. 0.0377 0.0332 0.0353
05:01-06:00, Mon., 06 Oct. 0.0380 0.0331 0.0355
04:01-05:00, Mon., 06 Oct. 0.0388 0.0329 0.0354
03:01-04:00, Mon., 06 Oct. 0.0366 0.0319 0.0348
02:01-03:00, Mon., 06 Oct. 0.0378 0.0324 0.0349
01:01-02:00, Mon., 06 Oct. 0.0374 0.0330 0.0349
00:01-01:00, Mon., 06 Oct. 0.0377 0.0322 0.0349
23:01-24:00, Sun., 05 Oct. 0.0361 0.0313 0.0338
22:01-23:00, Sun., 05 Oct. 0.0356 0.0321 0.0337
21:01-22:00, Sun., 05 Oct. 0.0367 0.0317 0.0341
20:01-21:00, Sun., 05 Oct. 0.0358 0.0315 0.0337
19:01-20:00, Sun., 05 Oct. 0.0363 0.0323 0.0339
18:01-19:00, Sun., 05 Oct. 0.0362 0.0316 0.0338
17:01-18:00, Sun., 05 Oct. 0.0356 0.0310 0.0338
16:01-17:00, Sun., 05 Oct. 0.0359 0.0310 0.0335
15:01-16:00, Sun., 05 Oct. 0.0367 0.0316 0.0339
14:01-15:00, Sun., 05 Oct. 0.0365 0.0309 0.0335
13:01-14:00, Sun., 05 Oct. 0.0361 0.0307 0.0337
12:01-13:00, Sun., 05 Oct. 0.0360 0.0309 0.0336
11:01-12:00, Sun., 05 Oct. 0.0360 0.0315 0.0339
10:01-11:00, Sun., 05 Oct. 0.0364 0.0315 0.0339
09:01-10:00, Sun., 05 Oct. 0.0373 0.0318 0.0340
08:01-09:00, Sun., 05 Oct. 0.0367 0.0312 0.0341
07:01-08:00, Sun., 05 Oct. 0.0370 0.0322 0.0344
06:01-07:00, Sun., 05 Oct. 0.0374 0.0315 0.0345
05:01-06:00, Sun., 05 Oct. 0.0374 0.0325 0.0347
04:01-05:00, Sun., 05 Oct. 0.0371 0.0327 0.0346
03:01-04:00, Sun., 05 Oct. 0.0370 0.0324 0.0345
02:01-03:00, Sun., 05 Oct. 0.0377 0.0316 0.0346
01:01-02:00, Sun., 05 Oct. 0.0367 0.0318 0.0344
00:01-01:00, Sun., 05 Oct. 0.0378 0.0322 0.0345
23:01-24:00, Sat., 04 Oct. 0.0365 0.0318 0.0343
22:01-23:00, Sat., 04 Oct. 0.0367 0.0320 0.0342
21:01-22:00, Sat., 04 Oct. 0.0367 0.0319 0.0343
20:01-21:00, Sat., 04 Oct. 0.0372 0.0322 0.0347
19:01-20:00, Sat., 04 Oct. 0.0389 0.0325 0.0364
18:01-19:00, Sat., 04 Oct. 0.0395 0.0337 0.0371
17:01-18:00, Sat., 04 Oct. 0.0392 0.0332 0.0361
16:01-17:00, Sat., 04 Oct. 0.0385 0.0329 0.0361
15:01-16:00, Sat., 04 Oct. 0.0375 0.0333 0.0355
14:01-15:00, Sat., 04 Oct. 0.0366 0.0322 0.0344
13:01-14:00, Sat., 04 Oct. 0.0368 0.0325 0.0343
12:01-13:00, Sat., 04 Oct. 0.0377 0.0329 0.0348
11:01-12:00, Sat., 04 Oct. 0.0382 0.0327 0.0358
10:01-11:00, Sat., 04 Oct. 0.0391 0.0338 0.0368
09:01-10:00, Sat., 04 Oct. 0.0375 0.0329 0.0350
08:01-09:00, Sat., 04 Oct. 0.0395 0.0326 0.0352
07:01-08:00, Sat., 04 Oct. 0.0389 0.0336 0.0358
06:01-07:00, Sat., 04 Oct. 0.0377 0.0334 0.0355
05:01-06:00, Sat., 04 Oct. 0.0384 0.0326 0.0358
04:01-05:00, Sat., 04 Oct. 0.0379 0.0338 0.0358
03:01-04:00, Sat., 04 Oct. 0.0375 0.0335 0.0356
02:01-03:00, Sat., 04 Oct. 0.0379 0.0333 0.0356
01:01-02:00, Sat., 04 Oct. 0.0379 0.0330 0.0350
00:01-01:00, Sat., 04 Oct. 0.0377 0.0316 0.0350
23:01-24:00, Fri., 03 Oct. 0.0380 0.0327 0.0350
22:01-23:00, Fri., 03 Oct. 0.0371 0.0318 0.0346
21:01-22:00, Fri., 03 Oct. 0.0367 0.0322 0.0349
20:01-21:00, Fri., 03 Oct. 0.0383 0.0329 0.0349
19:01-20:00, Fri., 03 Oct. 0.0374 0.0329 0.0347
18:01-19:00, Fri., 03 Oct. 0.0362 0.0313 0.0340
17:01-18:00, Fri., 03 Oct. 0.0373 0.0317 0.0342
16:01-17:00, Fri., 03 Oct. 0.0381 0.0322 0.0347
15:01-16:00, Fri., 03 Oct. 0.0364 0.0325 0.0346
14:01-15:00, Fri., 03 Oct. 0.0370 0.0318 0.0344
13:01-14:00, Fri., 03 Oct. 0.0374 0.0322 0.0345
12:01-13:00, Fri., 03 Oct. 0.0370 0.0321 0.0344
11:01-12:00, Fri., 03 Oct. 0.0371 0.0313 0.0343
10:01-11:00, Fri., 03 Oct. 0.0365 0.0316 0.0344
09:01-10:00, Fri., 03 Oct. 0.0372 0.0331 0.0349
08:01-09:00, Fri., 03 Oct. 0.0369 0.0329 0.0353
07:01-08:00, Fri., 03 Oct. 0.0378 0.0329 0.0352
06:01-07:00, Fri., 03 Oct. 0.0364 0.0324 0.0347
05:01-06:00, Fri., 03 Oct. 0.0368 0.0320 0.0344
04:01-05:00, Fri., 03 Oct. 0.0373 0.0321 0.0349
03:01-04:00, Fri., 03 Oct. 0.0381 0.0322 0.0353
02:01-03:00, Fri., 03 Oct. 0.0373 0.0329 0.0350
01:01-02:00, Fri., 03 Oct. 0.0374 0.0326 0.0349
00:01-01:00, Fri., 03 Oct. 0.0378 0.0323 0.0350
23:01-24:00, Thu., 02 Oct. 0.0374 0.0322 0.0351
22:01-23:00, Thu., 02 Oct. 0.0381 0.0325 0.0348
21:01-22:00, Thu., 02 Oct. 0.0379 0.0324 0.0346
20:01-21:00, Thu., 02 Oct. 0.0368 0.0322 0.0342
19:01-20:00, Thu., 02 Oct. 0.0369 0.0314 0.0342
18:01-19:00, Thu., 02 Oct. 0.0362 0.0315 0.0340
17:01-18:00, Thu., 02 Oct. 0.0368 0.0319 0.0343
16:01-17:00, Thu., 02 Oct. 0.0364 0.0308 0.0337
15:01-16:00, Thu., 02 Oct. 0.0359 0.0320 0.0340
14:01-15:00, Thu., 02 Oct. 0.0370 0.0315 0.0340
13:01-14:00, Thu., 02 Oct. 0.0364 0.0318 0.0339
12:01-13:00, Thu., 02 Oct. 0.0363 0.0316 0.0337
11:01-12:00, Thu., 02 Oct. 0.0370 0.0323 0.0343
10:01-11:00, Thu., 02 Oct. 0.0370 0.0321 0.0347
09:01-10:00, Thu., 02 Oct. 0.0380 0.0322 0.0349
08:01-09:00, Thu., 02 Oct. 0.0377 0.0317 0.0343
07:01-08:00, Thu., 02 Oct. 0.0363 0.0310 0.0335
06:01-07:00, Thu., 02 Oct. 0.0360 0.0322 0.0338
05:01-06:00, Thu., 02 Oct. 0.0362 0.0313 0.0339
04:01-05:00, Thu., 02 Oct. 0.0360 0.0314 0.0340
03:01-04:00, Thu., 02 Oct. 0.0364 0.0308 0.0339
02:01-03:00, Thu., 02 Oct. 0.0358 0.0304 0.0337
01:01-02:00, Thu., 02 Oct. 0.0363 0.0312 0.0337
00:01-01:00, Thu., 02 Oct. 0.0360 0.0313 0.0340
23:01-24:00, Wed., 01 Oct. 0.0369 0.0317 0.0341
22:01-23:00, Wed., 01 Oct. 0.0361 0.0307 0.0337