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

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.

We will suspend the provision of data in part or whole of the following time slots by interruption of power supply and relevant facilities due to maintenance and inspection of equipment.
        From 7:30 to 17:30 on Saturday, October 25, 2014

【News about this monitoring post】

We will suspend the provision of data in part or whole of the following time slots by interruption of power supply and relevant facilities due to maintenance and inspection of equipment.

From 9:00 to 13:00 on Tuesday, June 26,2018 Hachioji
From 13:00 to 17:00 on Thursday, June 26,2018 Adachi
From 9:00 to 13:00 on Wednesday, June 27,2018 Chofu
From 13:00 to 17:00 on Wednesday, June 27,2018 Ota
From 9:00 to 13:00 on Thursday, June 28,2018 Kodaira 
From 13:00 to 17:00 on Thursday, June 28,2018 Edogawa
From 9:00 to 13:00 on Friday, June 29,2018 Shinjuku







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, Thu., 20 Sep. 0.0470 0.0393 0.0422
20:01-21:00, Thu., 20 Sep. 0.0449 0.0358 0.0409
19:01-20:00, Thu., 20 Sep. 0.0432 0.0362 0.0392
18:01-19:00, Thu., 20 Sep. 0.0462 0.0364 0.0411
17:01-18:00, Thu., 20 Sep. 0.0525 0.0432 0.0482
16:01-17:00, Thu., 20 Sep. 0.0519 0.0426 0.0472
15:01-16:00, Thu., 20 Sep. 0.0452 0.0345 0.0402
14:01-15:00, Thu., 20 Sep. 0.0371 0.0295 0.0338
13:01-14:00, Thu., 20 Sep. 0.0317 0.0272 0.0298
12:01-13:00, Thu., 20 Sep. 0.0311 0.0276 0.0292
11:01-12:00, Thu., 20 Sep. 0.0308 0.0270 0.0292
10:01-11:00, Thu., 20 Sep. 0.0321 0.0277 0.0297
09:01-10:00, Thu., 20 Sep. 0.0310 0.0275 0.0293
08:01-09:00, Thu., 20 Sep. 0.0306 0.0272 0.0289
07:01-08:00, Thu., 20 Sep. 0.0305 0.0260 0.0286
06:01-07:00, Thu., 20 Sep. 0.0306 0.0273 0.0289
05:01-06:00, Thu., 20 Sep. 0.0305 0.0265 0.0286
04:01-05:00, Thu., 20 Sep. 0.0312 0.0271 0.0288
03:01-04:00, Thu., 20 Sep. 0.0302 0.0260 0.0285
02:01-03:00, Thu., 20 Sep. 0.0312 0.0271 0.0291
01:01-02:00, Thu., 20 Sep. 0.0302 0.0263 0.0284
00:01-01:00, Thu., 20 Sep. 0.0295 0.0263 0.0280
23:01-24:00, Wed., 19 Sep. 0.0307 0.0262 0.0281
22:01-23:00, Wed., 19 Sep. 0.0298 0.0263 0.0282
21:01-22:00, Wed., 19 Sep. 0.0301 0.0257 0.0279
20:01-21:00, Wed., 19 Sep. 0.0311 0.0266 0.0280
19:01-20:00, Wed., 19 Sep. 0.0305 0.0265 0.0282
18:01-19:00, Wed., 19 Sep. 0.0299 0.0264 0.0282
17:01-18:00, Wed., 19 Sep. 0.0298 0.0266 0.0282
16:01-17:00, Wed., 19 Sep. 0.0300 0.0259 0.0281
15:01-16:00, Wed., 19 Sep. 0.0302 0.0265 0.0282
14:01-15:00, Wed., 19 Sep. 0.0301 0.0268 0.0282
13:01-14:00, Wed., 19 Sep. 0.0297 0.0264 0.0283
12:01-13:00, Wed., 19 Sep. 0.0311 0.0257 0.0282
11:01-12:00, Wed., 19 Sep. 0.0305 0.0266 0.0284
10:01-11:00, Wed., 19 Sep. 0.0300 0.0265 0.0283
09:01-10:00, Wed., 19 Sep. 0.0295 0.0261 0.0281
08:01-09:00, Wed., 19 Sep. 0.0300 0.0267 0.0282
07:01-08:00, Wed., 19 Sep. 0.0302 0.0262 0.0283
06:01-07:00, Wed., 19 Sep. 0.0303 0.0266 0.0283
05:01-06:00, Wed., 19 Sep. 0.0298 0.0259 0.0280
04:01-05:00, Wed., 19 Sep. 0.0302 0.0266 0.0282
03:01-04:00, Wed., 19 Sep. 0.0303 0.0260 0.0280
02:01-03:00, Wed., 19 Sep. 0.0300 0.0254 0.0281
01:01-02:00, Wed., 19 Sep. 0.0301 0.0263 0.0277
00:01-01:00, Wed., 19 Sep. 0.0304 0.0265 0.0280
23:01-24:00, Tue., 18 Sep. 0.0304 0.0271 0.0290
22:01-23:00, Tue., 18 Sep. 0.0322 0.0271 0.0296
21:01-22:00, Tue., 18 Sep. 0.0319 0.0269 0.0295
20:01-21:00, Tue., 18 Sep. 0.0330 0.0264 0.0303
19:01-20:00, Tue., 18 Sep. 0.0291 0.0255 0.0274
18:01-19:00, Tue., 18 Sep. 0.0290 0.0260 0.0275
17:01-18:00, Tue., 18 Sep. 0.0293 0.0256 0.0275
16:01-17:00, Tue., 18 Sep. 0.0295 0.0257 0.0276
15:01-16:00, Tue., 18 Sep. 0.0294 0.0251 0.0274
14:01-15:00, Tue., 18 Sep. 0.0296 0.0255 0.0276
13:01-14:00, Tue., 18 Sep. 0.0289 0.0248 0.0274
12:01-13:00, Tue., 18 Sep. 0.0298 0.0258 0.0276
11:01-12:00, Tue., 18 Sep. 0.0296 0.0253 0.0276
10:01-11:00, Tue., 18 Sep. 0.0298 0.0253 0.0277
09:01-10:00, Tue., 18 Sep. 0.0296 0.0253 0.0275
08:01-09:00, Tue., 18 Sep. 0.0289 0.0258 0.0275
07:01-08:00, Tue., 18 Sep. 0.0297 0.0258 0.0277
06:01-07:00, Tue., 18 Sep. 0.0302 0.0250 0.0277
05:01-06:00, Tue., 18 Sep. 0.0293 0.0249 0.0274
04:01-05:00, Tue., 18 Sep. 0.0288 0.0250 0.0273
03:01-04:00, Tue., 18 Sep. 0.0291 0.0252 0.0272
02:01-03:00, Tue., 18 Sep. 0.0308 0.0265 0.0285
01:01-02:00, Tue., 18 Sep. 0.0354 0.0287 0.0318
00:01-01:00, Tue., 18 Sep. 0.0400 0.0317 0.0357
23:01-24:00, Mon., 17 Sep. 0.0333 0.0286 0.0311
22:01-23:00, Mon., 17 Sep. 0.0317 0.0264 0.0284
21:01-22:00, Mon., 17 Sep. 0.0295 0.0265 0.0282
20:01-21:00, Mon., 17 Sep. 0.0350 0.0272 0.0311
19:01-20:00, Mon., 17 Sep. 0.0453 0.0328 0.0369
18:01-19:00, Mon., 17 Sep. 0.0665 0.0387 0.0534
17:01-18:00, Mon., 17 Sep. 0.0676 0.0260 0.0417
16:01-17:00, Mon., 17 Sep. 0.0310 0.0260 0.0281
15:01-16:00, Mon., 17 Sep. 0.0303 0.0271 0.0287
14:01-15:00, Mon., 17 Sep. 0.0300 0.0265 0.0286
13:01-14:00, Mon., 17 Sep. 0.0300 0.0267 0.0287
12:01-13:00, Mon., 17 Sep. 0.0307 0.0261 0.0287
11:01-12:00, Mon., 17 Sep. 0.0311 0.0267 0.0290
10:01-11:00, Mon., 17 Sep. 0.0306 0.0272 0.0290
09:01-10:00, Mon., 17 Sep. 0.0310 0.0272 0.0293
08:01-09:00, Mon., 17 Sep. 0.0311 0.0270 0.0290
07:01-08:00, Mon., 17 Sep. 0.0316 0.0282 0.0297
06:01-07:00, Mon., 17 Sep. 0.0310 0.0271 0.0293
05:01-06:00, Mon., 17 Sep. 0.0305 0.0271 0.0288
04:01-05:00, Mon., 17 Sep. 0.0303 0.0262 0.0283
03:01-04:00, Mon., 17 Sep. 0.0299 0.0266 0.0280
02:01-03:00, Mon., 17 Sep. 0.0297 0.0261 0.0281
01:01-02:00, Mon., 17 Sep. 0.0298 0.0254 0.0278
00:01-01:00, Mon., 17 Sep. 0.0297 0.0253 0.0277
23:01-24:00, Sun., 16 Sep. 0.0296 0.0261 0.0277
22:01-23:00, Sun., 16 Sep. 0.0306 0.0260 0.0277
21:01-22:00, Sun., 16 Sep. 0.0296 0.0260 0.0279
20:01-21:00, Sun., 16 Sep. 0.0311 0.0256 0.0276
19:01-20:00, Sun., 16 Sep. 0.0297 0.0254 0.0277
18:01-19:00, Sun., 16 Sep. 0.0298 0.0256 0.0276
17:01-18:00, Sun., 16 Sep. 0.0308 0.0259 0.0278
16:01-17:00, Sun., 16 Sep. 0.0312 0.0258 0.0277
15:01-16:00, Sun., 16 Sep. 0.0297 0.0252 0.0277
14:01-15:00, Sun., 16 Sep. 0.0295 0.0261 0.0277
13:01-14:00, Sun., 16 Sep. 0.0298 0.0259 0.0278
12:01-13:00, Sun., 16 Sep. 0.0300 0.0257 0.0275
11:01-12:00, Sun., 16 Sep. 0.0295 0.0258 0.0275
10:01-11:00, Sun., 16 Sep. 0.0300 0.0252 0.0276
09:01-10:00, Sun., 16 Sep. 0.0288 0.0255 0.0274
08:01-09:00, Sun., 16 Sep. 0.0298 0.0257 0.0278
07:01-08:00, Sun., 16 Sep. 0.0296 0.0260 0.0278
06:01-07:00, Sun., 16 Sep. 0.0298 0.0258 0.0279
05:01-06:00, Sun., 16 Sep. 0.0299 0.0258 0.0279
04:01-05:00, Sun., 16 Sep. 0.0295 0.0253 0.0278
03:01-04:00, Sun., 16 Sep. 0.0302 0.0259 0.0279
02:01-03:00, Sun., 16 Sep. 0.0300 0.0265 0.0284
01:01-02:00, Sun., 16 Sep. 0.0296 0.0248 0.0279
00:01-01:00, Sun., 16 Sep. 0.0304 0.0266 0.0282
23:01-24:00, Sat., 15 Sep. 0.0292 0.0258 0.0277
22:01-23:00, Sat., 15 Sep. 0.0307 0.0257 0.0275
21:01-22:00, Sat., 15 Sep. 0.0289 0.0259 0.0273
20:01-21:00, Sat., 15 Sep. 0.0291 0.0253 0.0274
19:01-20:00, Sat., 15 Sep. 0.0298 0.0253 0.0271
18:01-19:00, Sat., 15 Sep. 0.0292 0.0258 0.0274
17:01-18:00, Sat., 15 Sep. 0.0297 0.0258 0.0272
16:01-17:00, Sat., 15 Sep. 0.0290 0.0248 0.0273
15:01-16:00, Sat., 15 Sep. 0.0304 0.0256 0.0280
14:01-15:00, Sat., 15 Sep. 0.0322 0.0269 0.0297
13:01-14:00, Sat., 15 Sep. 0.0334 0.0293 0.0312
12:01-13:00, Sat., 15 Sep. 0.0327 0.0285 0.0304
11:01-12:00, Sat., 15 Sep. 0.0346 0.0295 0.0320
10:01-11:00, Sat., 15 Sep. 0.0352 0.0306 0.0324
09:01-10:00, Sat., 15 Sep. 0.0348 0.0301 0.0323
08:01-09:00, Sat., 15 Sep. 0.0384 0.0299 0.0341
07:01-08:00, Sat., 15 Sep. 0.0352 0.0274 0.0316
06:01-07:00, Sat., 15 Sep. 0.0292 0.0258 0.0274
05:01-06:00, Sat., 15 Sep. 0.0293 0.0257 0.0277
04:01-05:00, Sat., 15 Sep. 0.0298 0.0258 0.0278
03:01-04:00, Sat., 15 Sep. 0.0304 0.0268 0.0287
02:01-03:00, Sat., 15 Sep. 0.0332 0.0280 0.0300
01:01-02:00, Sat., 15 Sep. 0.0332 0.0284 0.0308
00:01-01:00, Sat., 15 Sep. 0.0324 0.0287 0.0304
23:01-24:00, Fri., 14 Sep. 0.0319 0.0263 0.0295
22:01-23:00, Fri., 14 Sep. 0.0314 0.0270 0.0291
21:01-22:00, Fri., 14 Sep. 0.0314 0.0259 0.0288
20:01-21:00, Fri., 14 Sep. 0.0290 0.0253 0.0275
19:01-20:00, Fri., 14 Sep. 0.0288 0.0253 0.0275
18:01-19:00, Fri., 14 Sep. 0.0292 0.0257 0.0274
17:01-18:00, Fri., 14 Sep. 0.0295 0.0251 0.0274
16:01-17:00, Fri., 14 Sep. 0.0302 0.0258 0.0273
15:01-16:00, Fri., 14 Sep. 0.0288 0.0258 0.0273
14:01-15:00, Fri., 14 Sep. 0.0294 0.0251 0.0272
13:01-14:00, Fri., 14 Sep. 0.0290 0.0251 0.0273
12:01-13:00, Fri., 14 Sep. 0.0295 0.0256 0.0274
11:01-12:00, Fri., 14 Sep. 0.0301 0.0257 0.0279
10:01-11:00, Fri., 14 Sep. 0.0309 0.0260 0.0287
09:01-10:00, Fri., 14 Sep. 0.0316 0.0280 0.0296
08:01-09:00, Fri., 14 Sep. 0.0327 0.0285 0.0305
07:01-08:00, Fri., 14 Sep. 0.0330 0.0294 0.0312
06:01-07:00, Fri., 14 Sep. 0.0331 0.0279 0.0306
05:01-06:00, Fri., 14 Sep. 0.0304 0.0268 0.0285
04:01-05:00, Fri., 14 Sep. 0.0299 0.0262 0.0282
03:01-04:00, Fri., 14 Sep. 0.0303 0.0260 0.0284
02:01-03:00, Fri., 14 Sep. 0.0310 0.0268 0.0290
01:01-02:00, Fri., 14 Sep. 0.0338 0.0284 0.0305
00:01-01:00, Fri., 14 Sep. 0.0322 0.0287 0.0305
23:01-24:00, Thu., 13 Sep. 0.0314 0.0280 0.0297
22:01-23:00, Thu., 13 Sep. 0.0313 0.0267 0.0289
21:01-22:00, Thu., 13 Sep. 0.0316 0.0274 0.0298
20:01-21:00, Thu., 13 Sep. 0.0324 0.0276 0.0295
19:01-20:00, Thu., 13 Sep. 0.0301 0.0259 0.0281
18:01-19:00, Thu., 13 Sep. 0.0298 0.0256 0.0276
17:01-18:00, Thu., 13 Sep. 0.0297 0.0259 0.0278
16:01-17:00, Thu., 13 Sep. 0.0297 0.0257 0.0279
15:01-16:00, Thu., 13 Sep. 0.0296 0.0263 0.0280
14:01-15:00, Thu., 13 Sep. 0.0296 0.0251 0.0280
13:01-14:00, Thu., 13 Sep. 0.0295 0.0261 0.0278
12:01-13:00, Thu., 13 Sep. 0.0302 0.0255 0.0278
11:01-12:00, Thu., 13 Sep. 0.0300 0.0257 0.0281
10:01-11:00, Thu., 13 Sep. 0.0306 0.0254 0.0279
09:01-10:00, Thu., 13 Sep. 0.0298 0.0259 0.0282
08:01-09:00, Thu., 13 Sep. 0.0304 0.0264 0.0283
07:01-08:00, Thu., 13 Sep. 0.0307 0.0265 0.0286
06:01-07:00, Thu., 13 Sep. 0.0306 0.0266 0.0285
05:01-06:00, Thu., 13 Sep. 0.0311 0.0267 0.0284
04:01-05:00, Thu., 13 Sep. 0.0316 0.0266 0.0286
03:01-04:00, Thu., 13 Sep. 0.0323 0.0264 0.0284
02:01-03:00, Thu., 13 Sep. 0.0301 0.0258 0.0281
01:01-02:00, Thu., 13 Sep. 0.0300 0.0263 0.0281
00:01-01:00, Thu., 13 Sep. 0.0303 0.0261 0.0280
23:01-24:00, Wed., 12 Sep. 0.0309 0.0261 0.0281
22:01-23:00, Wed., 12 Sep. 0.0304 0.0264 0.0284
21:01-22:00, Wed., 12 Sep. 0.0302 0.0262 0.0284
20:01-21:00, Wed., 12 Sep. 0.0310 0.0271 0.0288
19:01-20:00, Wed., 12 Sep. 0.0294 0.0250 0.0276
18:01-19:00, Wed., 12 Sep. 0.0298 0.0258 0.0276
17:01-18:00, Wed., 12 Sep. 0.0298 0.0256 0.0274
16:01-17:00, Wed., 12 Sep. 0.0295 0.0257 0.0274
15:01-16:00, Wed., 12 Sep. 0.0292 0.0254 0.0272
14:01-15:00, Wed., 12 Sep. 0.0290 0.0245 0.0273
13:01-14:00, Wed., 12 Sep. 0.0292 0.0255 0.0277
12:01-13:00, Wed., 12 Sep. 0.0293 0.0254 0.0273
11:01-12:00, Wed., 12 Sep. 0.0299 0.0263 0.0276
10:01-11:00, Wed., 12 Sep. 0.0301 0.0260 0.0276
09:01-10:00, Wed., 12 Sep. 0.0296 0.0258 0.0276
08:01-09:00, Wed., 12 Sep. 0.0296 0.0254 0.0278
07:01-08:00, Wed., 12 Sep. 0.0302 0.0257 0.0280
06:01-07:00, Wed., 12 Sep. 0.0298 0.0257 0.0279
05:01-06:00, Wed., 12 Sep. 0.0294 0.0263 0.0279
04:01-05:00, Wed., 12 Sep. 0.0297 0.0258 0.0276
03:01-04:00, Wed., 12 Sep. 0.0291 0.0254 0.0274
02:01-03:00, Wed., 12 Sep. 0.0292 0.0255 0.0276
01:01-02:00, Wed., 12 Sep. 0.0295 0.0250 0.0275
00:01-01:00, Wed., 12 Sep. 0.0296 0.0246 0.0275
23:01-24:00, Tue., 11 Sep. 0.0292 0.0255 0.0274
22:01-23:00, Tue., 11 Sep. 0.0295 0.0258 0.0274
21:01-22:00, Tue., 11 Sep. 0.0297 0.0259 0.0274
20:01-21:00, Tue., 11 Sep. 0.0291 0.0254 0.0272
19:01-20:00, Tue., 11 Sep. 0.0297 0.0256 0.0270
18:01-19:00, Tue., 11 Sep. 0.0292 0.0256 0.0274
17:01-18:00, Tue., 11 Sep. 0.0294 0.0259 0.0276
16:01-17:00, Tue., 11 Sep. 0.0290 0.0254 0.0275
15:01-16:00, Tue., 11 Sep. 0.0290 0.0254 0.0275
14:01-15:00, Tue., 11 Sep. 0.0297 0.0255 0.0275
13:01-14:00, Tue., 11 Sep. 0.0301 0.0252 0.0276
12:01-13:00, Tue., 11 Sep. 0.0296 0.0256 0.0276
11:01-12:00, Tue., 11 Sep. 0.0295 0.0256 0.0275
10:01-11:00, Tue., 11 Sep. 0.0295 0.0257 0.0276
09:01-10:00, Tue., 11 Sep. 0.0302 0.0259 0.0276
08:01-09:00, Tue., 11 Sep. 0.0294 0.0250 0.0276
07:01-08:00, Tue., 11 Sep. 0.0289 0.0260 0.0275
06:01-07:00, Tue., 11 Sep. 0.0297 0.0258 0.0281
05:01-06:00, Tue., 11 Sep. 0.0315 0.0264 0.0293
04:01-05:00, Tue., 11 Sep. 0.0381 0.0295 0.0338
03:01-04:00, Tue., 11 Sep. 0.0433 0.0342 0.0389
02:01-03:00, Tue., 11 Sep. 0.0380 0.0310 0.0343
01:01-02:00, Tue., 11 Sep. 0.0384 0.0334 0.0360
00:01-01:00, Tue., 11 Sep. 0.0398 0.0300 0.0345
23:01-24:00, Mon., 10 Sep. 0.0339 0.0303 0.0319
22:01-23:00, Mon., 10 Sep. 0.0326 0.0284 0.0305