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
06:01-07:00, Sun., 14 Sep. 0.0382 0.0319 0.0352
05:01-06:00, Sun., 14 Sep. 0.0357 0.0316 0.0338
04:01-05:00, Sun., 14 Sep. 0.0362 0.0313 0.0339
03:01-04:00, Sun., 14 Sep. 0.0363 0.0312 0.0339
02:01-03:00, Sun., 14 Sep. 0.0364 0.0319 0.0339
01:01-02:00, Sun., 14 Sep. 0.0363 0.0304 0.0333
00:01-01:00, Sun., 14 Sep. 0.0356 0.0309 0.0333
23:01-24:00, Sat., 13 Sep. 0.0349 0.0306 0.0327
22:01-23:00, Sat., 13 Sep. 0.0347 0.0297 0.0328
21:01-22:00, Sat., 13 Sep. 0.0349 0.0308 0.0329
20:01-21:00, Sat., 13 Sep. 0.0356 0.0309 0.0330
19:01-20:00, Sat., 13 Sep. 0.0351 0.0308 0.0331
18:01-19:00, Sat., 13 Sep. 0.0363 0.0315 0.0332
17:01-18:00, Sat., 13 Sep. 0.0356 0.0311 0.0331
16:01-17:00, Sat., 13 Sep. 0.0354 0.0306 0.0328
15:01-16:00, Sat., 13 Sep. 0.0358 0.0308 0.0328
14:01-15:00, Sat., 13 Sep. 0.0353 0.0305 0.0330
13:01-14:00, Sat., 13 Sep. 0.0356 0.0306 0.0330
12:01-13:00, Sat., 13 Sep. 0.0348 0.0301 0.0331
11:01-12:00, Sat., 13 Sep. 0.0360 0.0308 0.0332
10:01-11:00, Sat., 13 Sep. 0.0363 0.0295 0.0332
09:01-10:00, Sat., 13 Sep. 0.0369 0.0306 0.0337
08:01-09:00, Sat., 13 Sep. 0.0363 0.0322 0.0344
07:01-08:00, Sat., 13 Sep. 0.0370 0.0319 0.0343
06:01-07:00, Sat., 13 Sep. 0.0374 0.0322 0.0346
05:01-06:00, Sat., 13 Sep. 0.0362 0.0314 0.0339
04:01-05:00, Sat., 13 Sep. 0.0367 0.0318 0.0336
03:01-04:00, Sat., 13 Sep. 0.0369 0.0316 0.0342
02:01-03:00, Sat., 13 Sep. 0.0373 0.0333 0.0352
01:01-02:00, Sat., 13 Sep. 0.0383 0.0327 0.0356
00:01-01:00, Sat., 13 Sep. 0.0391 0.0339 0.0363
23:01-24:00, Fri., 12 Sep. 0.0375 0.0324 0.0351
22:01-23:00, Fri., 12 Sep. 0.0397 0.0332 0.0363
21:01-22:00, Fri., 12 Sep. 0.0402 0.0344 0.0373
20:01-21:00, Fri., 12 Sep. 0.0395 0.0336 0.0363
19:01-20:00, Fri., 12 Sep. 0.0374 0.0329 0.0350
18:01-19:00, Fri., 12 Sep. 0.0362 0.0319 0.0341
17:01-18:00, Fri., 12 Sep. 0.0367 0.0319 0.0339
16:01-17:00, Fri., 12 Sep. 0.0364 0.0324 0.0346
15:01-16:00, Fri., 12 Sep. 0.0366 0.0317 0.0338
14:01-15:00, Fri., 12 Sep. 0.0366 0.0309 0.0340
13:01-14:00, Fri., 12 Sep. 0.0364 0.0320 0.0339
12:01-13:00, Fri., 12 Sep. 0.0366 0.0320 0.0339
11:01-12:00, Fri., 12 Sep. 0.0366 0.0308 0.0338
10:01-11:00, Fri., 12 Sep. 0.0360 0.0311 0.0335
09:01-10:00, Fri., 12 Sep. 0.0363 0.0316 0.0338
08:01-09:00, Fri., 12 Sep. 0.0358 0.0308 0.0333
07:01-08:00, Fri., 12 Sep. 0.0356 0.0308 0.0335
06:01-07:00, Fri., 12 Sep. 0.0358 0.0311 0.0334
05:01-06:00, Fri., 12 Sep. 0.0361 0.0308 0.0334
04:01-05:00, Fri., 12 Sep. 0.0352 0.0311 0.0334
03:01-04:00, Fri., 12 Sep. 0.0367 0.0304 0.0336
02:01-03:00, Fri., 12 Sep. 0.0362 0.0323 0.0343
01:01-02:00, Fri., 12 Sep. 0.0426 0.0329 0.0372
00:01-01:00, Fri., 12 Sep. 0.0464 0.0366 0.0427
23:01-24:00, Thu., 11 Sep. 0.0493 0.0349 0.0426
22:01-23:00, Thu., 11 Sep. 0.0390 0.0319 0.0348
21:01-22:00, Thu., 11 Sep. 0.0372 0.0322 0.0351
20:01-21:00, Thu., 11 Sep. 0.0390 0.0343 0.0366
19:01-20:00, Thu., 11 Sep. 0.0394 0.0329 0.0364
18:01-19:00, Thu., 11 Sep. 0.0359 0.0319 0.0339
17:01-18:00, Thu., 11 Sep. 0.0360 0.0318 0.0338
16:01-17:00, Thu., 11 Sep. 0.0375 0.0317 0.0348
15:01-16:00, Thu., 11 Sep. 0.0422 0.0341 0.0378
14:01-15:00, Thu., 11 Sep. 0.0426 0.0318 0.0375
13:01-14:00, Thu., 11 Sep. 0.0374 0.0315 0.0343
12:01-13:00, Thu., 11 Sep. 0.0369 0.0318 0.0345
11:01-12:00, Thu., 11 Sep. 0.0368 0.0324 0.0344
10:01-11:00, Thu., 11 Sep. 0.0383 0.0323 0.0347
09:01-10:00, Thu., 11 Sep. 0.0366 0.0321 0.0349
08:01-09:00, Thu., 11 Sep. 0.0377 0.0338 0.0356
07:01-08:00, Thu., 11 Sep. 0.0383 0.0315 0.0353
06:01-07:00, Thu., 11 Sep. 0.0370 0.0322 0.0351
05:01-06:00, Thu., 11 Sep. 0.0375 0.0314 0.0350
04:01-05:00, Thu., 11 Sep. 0.0365 0.0320 0.0341
03:01-04:00, Thu., 11 Sep. 0.0378 0.0323 0.0348
02:01-03:00, Thu., 11 Sep. 0.0373 0.0312 0.0346
01:01-02:00, Thu., 11 Sep. 0.0367 0.0322 0.0340
00:01-01:00, Thu., 11 Sep. 0.0365 0.0322 0.0340
23:01-24:00, Wed., 10 Sep. 0.0362 0.0321 0.0339
22:01-23:00, Wed., 10 Sep. 0.0367 0.0316 0.0337
21:01-22:00, Wed., 10 Sep. 0.0363 0.0315 0.0339
20:01-21:00, Wed., 10 Sep. 0.0357 0.0312 0.0338
19:01-20:00, Wed., 10 Sep. 0.0363 0.0319 0.0339
18:01-19:00, Wed., 10 Sep. 0.0360 0.0301 0.0337
17:01-18:00, Wed., 10 Sep. 0.0353 0.0308 0.0336
16:01-17:00, Wed., 10 Sep. 0.0360 0.0318 0.0338
15:01-16:00, Wed., 10 Sep. 0.0356 0.0313 0.0336
14:01-15:00, Wed., 10 Sep. 0.0353 0.0307 0.0337
13:01-14:00, Wed., 10 Sep. 0.0370 0.0325 0.0344
12:01-13:00, Wed., 10 Sep. 0.0387 0.0322 0.0360
11:01-12:00, Wed., 10 Sep. 0.0391 0.0329 0.0354
10:01-11:00, Wed., 10 Sep. 0.0372 0.0322 0.0348
09:01-10:00, Wed., 10 Sep. 0.0374 0.0325 0.0351
08:01-09:00, Wed., 10 Sep. 0.0375 0.0326 0.0351
07:01-08:00, Wed., 10 Sep. 0.0376 0.0336 0.0352
06:01-07:00, Wed., 10 Sep. 0.0378 0.0324 0.0352
05:01-06:00, Wed., 10 Sep. 0.0381 0.0326 0.0355
04:01-05:00, Wed., 10 Sep. 0.0368 0.0327 0.0352
03:01-04:00, Wed., 10 Sep. 0.0381 0.0336 0.0360
02:01-03:00, Wed., 10 Sep. 0.0399 0.0350 0.0375
01:01-02:00, Wed., 10 Sep. 0.0379 0.0332 0.0362
00:01-01:00, Wed., 10 Sep. 0.0379 0.0336 0.0354
23:01-24:00, Tue., 09 Sep. 0.0372 0.0324 0.0350
22:01-23:00, Tue., 09 Sep. 0.0382 0.0329 0.0349
21:01-22:00, Tue., 09 Sep. 0.0370 0.0325 0.0348
20:01-21:00, Tue., 09 Sep. 0.0370 0.0329 0.0348
19:01-20:00, Tue., 09 Sep. 0.0374 0.0322 0.0346
18:01-19:00, Tue., 09 Sep. 0.0379 0.0325 0.0347
17:01-18:00, Tue., 09 Sep. 0.0368 0.0323 0.0346
16:01-17:00, Tue., 09 Sep. 0.0374 0.0321 0.0346
15:01-16:00, Tue., 09 Sep. 0.0370 0.0322 0.0346
14:01-15:00, Tue., 09 Sep. 0.0361 0.0316 0.0342
13:01-14:00, Tue., 09 Sep. 0.0370 0.0315 0.0342
12:01-13:00, Tue., 09 Sep. 0.0377 0.0316 0.0347
11:01-12:00, Tue., 09 Sep. 0.0371 0.0324 0.0346
10:01-11:00, Tue., 09 Sep. 0.0369 0.0320 0.0345
09:01-10:00, Tue., 09 Sep. 0.0391 0.0325 0.0352
08:01-09:00, Tue., 09 Sep. 0.0369 0.0329 0.0351
07:01-08:00, Tue., 09 Sep. 0.0374 0.0325 0.0350
06:01-07:00, Tue., 09 Sep. 0.0374 0.0332 0.0352
05:01-06:00, Tue., 09 Sep. 0.0390 0.0334 0.0355
04:01-05:00, Tue., 09 Sep. 0.0374 0.0326 0.0348
03:01-04:00, Tue., 09 Sep. 0.0376 0.0325 0.0351
02:01-03:00, Tue., 09 Sep. 0.0374 0.0323 0.0345
01:01-02:00, Tue., 09 Sep. 0.0367 0.0325 0.0346
00:01-01:00, Tue., 09 Sep. 0.0372 0.0324 0.0347
23:01-24:00, Mon., 08 Sep. 0.0375 0.0326 0.0347
22:01-23:00, Mon., 08 Sep. 0.0368 0.0325 0.0347
21:01-22:00, Mon., 08 Sep. 0.0373 0.0318 0.0344
20:01-21:00, Mon., 08 Sep. 0.0369 0.0325 0.0344
19:01-20:00, Mon., 08 Sep. 0.0383 0.0306 0.0343
18:01-19:00, Mon., 08 Sep. 0.0360 0.0317 0.0341
17:01-18:00, Mon., 08 Sep. 0.0368 0.0322 0.0345
16:01-17:00, Mon., 08 Sep. 0.0363 0.0319 0.0342
15:01-16:00, Mon., 08 Sep. 0.0360 0.0318 0.0341
14:01-15:00, Mon., 08 Sep. 0.0362 0.0323 0.0341
13:01-14:00, Mon., 08 Sep. 0.0374 0.0326 0.0347
12:01-13:00, Mon., 08 Sep. 0.0371 0.0318 0.0347
11:01-12:00, Mon., 08 Sep. 0.0380 0.0330 0.0352
10:01-11:00, Mon., 08 Sep. 0.0381 0.0325 0.0355
09:01-10:00, Mon., 08 Sep. 0.0384 0.0339 0.0360
08:01-09:00, Mon., 08 Sep. 0.0390 0.0334 0.0363
07:01-08:00, Mon., 08 Sep. 0.0388 0.0346 0.0363
06:01-07:00, Mon., 08 Sep. 0.0381 0.0345 0.0362
05:01-06:00, Mon., 08 Sep. 0.0395 0.0338 0.0361
04:01-05:00, Mon., 08 Sep. 0.0391 0.0323 0.0362
03:01-04:00, Mon., 08 Sep. 0.0387 0.0334 0.0361
02:01-03:00, Mon., 08 Sep. 0.0391 0.0339 0.0363
01:01-02:00, Mon., 08 Sep. 0.0384 0.0332 0.0360
00:01-01:00, Mon., 08 Sep. 0.0381 0.0330 0.0358
23:01-24:00, Sun., 07 Sep. 0.0376 0.0330 0.0355
22:01-23:00, Sun., 07 Sep. 0.0371 0.0325 0.0347
21:01-22:00, Sun., 07 Sep. 0.0367 0.0318 0.0340
20:01-21:00, Sun., 07 Sep. 0.0360 0.0311 0.0339
19:01-20:00, Sun., 07 Sep. 0.0367 0.0319 0.0339
18:01-19:00, Sun., 07 Sep. 0.0359 0.0318 0.0339
17:01-18:00, Sun., 07 Sep. 0.0358 0.0308 0.0335
16:01-17:00, Sun., 07 Sep. 0.0361 0.0313 0.0339
15:01-16:00, Sun., 07 Sep. 0.0360 0.0307 0.0335
14:01-15:00, Sun., 07 Sep. 0.0361 0.0314 0.0340
13:01-14:00, Sun., 07 Sep. 0.0363 0.0309 0.0337
12:01-13:00, Sun., 07 Sep. 0.0360 0.0318 0.0337
11:01-12:00, Sun., 07 Sep. 0.0365 0.0312 0.0340
10:01-11:00, Sun., 07 Sep. 0.0374 0.0316 0.0342
09:01-10:00, Sun., 07 Sep. 0.0370 0.0313 0.0344
08:01-09:00, Sun., 07 Sep. 0.0373 0.0332 0.0351
07:01-08:00, Sun., 07 Sep. 0.0374 0.0329 0.0351
06:01-07:00, Sun., 07 Sep. 0.0387 0.0328 0.0351
05:01-06:00, Sun., 07 Sep. 0.0381 0.0322 0.0354
04:01-05:00, Sun., 07 Sep. 0.0389 0.0336 0.0359
03:01-04:00, Sun., 07 Sep. 0.0380 0.0316 0.0351
02:01-03:00, Sun., 07 Sep. 0.0369 0.0311 0.0343
01:01-02:00, Sun., 07 Sep. 0.0363 0.0313 0.0340
00:01-01:00, Sun., 07 Sep. 0.0360 0.0311 0.0339
23:01-24:00, Sat., 06 Sep. 0.0360 0.0307 0.0337
22:01-23:00, Sat., 06 Sep. 0.0356 0.0321 0.0338
21:01-22:00, Sat., 06 Sep. 0.0364 0.0321 0.0340
20:01-21:00, Sat., 06 Sep. 0.0364 0.0315 0.0339
19:01-20:00, Sat., 06 Sep. 0.0359 0.0316 0.0339
18:01-19:00, Sat., 06 Sep. 0.0366 0.0311 0.0339
17:01-18:00, Sat., 06 Sep. 0.0364 0.0320 0.0338
16:01-17:00, Sat., 06 Sep. 0.0363 0.0315 0.0339
15:01-16:00, Sat., 06 Sep. 0.0365 0.0307 0.0337
14:01-15:00, Sat., 06 Sep. 0.0364 0.0318 0.0335
13:01-14:00, Sat., 06 Sep. 0.0383 0.0313 0.0337
12:01-13:00, Sat., 06 Sep. 0.0365 0.0316 0.0340
11:01-12:00, Sat., 06 Sep. 0.0369 0.0314 0.0342
10:01-11:00, Sat., 06 Sep. 0.0375 0.0321 0.0347
09:01-10:00, Sat., 06 Sep. 0.0359 0.0319 0.0342
08:01-09:00, Sat., 06 Sep. 0.0370 0.0325 0.0345
07:01-08:00, Sat., 06 Sep. 0.0375 0.0319 0.0345
06:01-07:00, Sat., 06 Sep. 0.0378 0.0317 0.0346
05:01-06:00, Sat., 06 Sep. 0.0372 0.0325 0.0348
04:01-05:00, Sat., 06 Sep. 0.0378 0.0325 0.0348
03:01-04:00, Sat., 06 Sep. 0.0369 0.0314 0.0346
02:01-03:00, Sat., 06 Sep. 0.0367 0.0327 0.0345
01:01-02:00, Sat., 06 Sep. 0.0368 0.0308 0.0343
00:01-01:00, Sat., 06 Sep. 0.0373 0.0328 0.0349
23:01-24:00, Fri., 05 Sep. 0.0374 0.0326 0.0348
22:01-23:00, Fri., 05 Sep. 0.0380 0.0323 0.0345
21:01-22:00, Fri., 05 Sep. 0.0368 0.0317 0.0345
20:01-21:00, Fri., 05 Sep. 0.0380 0.0320 0.0341
19:01-20:00, Fri., 05 Sep. 0.0362 0.0310 0.0340
18:01-19:00, Fri., 05 Sep. 0.0371 0.0311 0.0340
17:01-18:00, Fri., 05 Sep. 0.0370 0.0324 0.0343
16:01-17:00, Fri., 05 Sep. 0.0369 0.0322 0.0348
15:01-16:00, Fri., 05 Sep. 0.0397 0.0339 0.0374
14:01-15:00, Fri., 05 Sep. 0.0410 0.0353 0.0389
13:01-14:00, Fri., 05 Sep. 0.0415 0.0357 0.0385
12:01-13:00, Fri., 05 Sep. 0.0405 0.0346 0.0374
11:01-12:00, Fri., 05 Sep. 0.0384 0.0323 0.0346
10:01-11:00, Fri., 05 Sep. 0.0364 0.0318 0.0338
09:01-10:00, Fri., 05 Sep. 0.0366 0.0315 0.0340
08:01-09:00, Fri., 05 Sep. 0.0378 0.0325 0.0348
07:01-08:00, Fri., 05 Sep. 0.0367 0.0327 0.0347
06:01-07:00, Fri., 05 Sep. 0.0382 0.0327 0.0350
05:01-06:00, Fri., 05 Sep. 0.0372 0.0325 0.0348
04:01-05:00, Fri., 05 Sep. 0.0376 0.0326 0.0351
03:01-04:00, Fri., 05 Sep. 0.0383 0.0340 0.0358
02:01-03:00, Fri., 05 Sep. 0.0376 0.0322 0.0353
01:01-02:00, Fri., 05 Sep. 0.0377 0.0334 0.0353
00:01-01:00, Fri., 05 Sep. 0.0379 0.0322 0.0355
23:01-24:00, Thu., 04 Sep. 0.0380 0.0331 0.0356
22:01-23:00, Thu., 04 Sep. 0.0377 0.0331 0.0354
21:01-22:00, Thu., 04 Sep. 0.0378 0.0333 0.0354
20:01-21:00, Thu., 04 Sep. 0.0384 0.0333 0.0356
19:01-20:00, Thu., 04 Sep. 0.0383 0.0336 0.0360
18:01-19:00, Thu., 04 Sep. 0.0390 0.0342 0.0366
17:01-18:00, Thu., 04 Sep. 0.0422 0.0357 0.0384
16:01-17:00, Thu., 04 Sep. 0.0451 0.0343 0.0409
15:01-16:00, Thu., 04 Sep. 0.0392 0.0345 0.0367
14:01-15:00, Thu., 04 Sep. 0.0395 0.0340 0.0363
13:01-14:00, Thu., 04 Sep. 0.0396 0.0337 0.0363
12:01-13:00, Thu., 04 Sep. 0.0384 0.0334 0.0361
11:01-12:00, Thu., 04 Sep. 0.0384 0.0345 0.0362
10:01-11:00, Thu., 04 Sep. 0.0384 0.0349 0.0366
09:01-10:00, Thu., 04 Sep. 0.0398 0.0346 0.0367
08:01-09:00, Thu., 04 Sep. 0.0388 0.0336 0.0364
07:01-08:00, Thu., 04 Sep. 0.0395 0.0339 0.0368