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
19:01-20:00, Sun., 24 Jun. 0.0299 0.0251 0.0275
18:01-19:00, Sun., 24 Jun. 0.0294 0.0264 0.0279
17:01-18:00, Sun., 24 Jun. 0.0299 0.0263 0.0279
16:01-17:00, Sun., 24 Jun. 0.0301 0.0260 0.0278
15:01-16:00, Sun., 24 Jun. 0.0295 0.0258 0.0276
14:01-15:00, Sun., 24 Jun. 0.0297 0.0254 0.0276
13:01-14:00, Sun., 24 Jun. 0.0299 0.0258 0.0277
12:01-13:00, Sun., 24 Jun. 0.0294 0.0266 0.0280
11:01-12:00, Sun., 24 Jun. 0.0302 0.0262 0.0283
10:01-11:00, Sun., 24 Jun. 0.0327 0.0270 0.0297
09:01-10:00, Sun., 24 Jun. 0.0328 0.0273 0.0297
08:01-09:00, Sun., 24 Jun. 0.0334 0.0283 0.0306
07:01-08:00, Sun., 24 Jun. 0.0326 0.0286 0.0307
06:01-07:00, Sun., 24 Jun. 0.0370 0.0306 0.0345
05:01-06:00, Sun., 24 Jun. 0.0393 0.0282 0.0322
04:01-05:00, Sun., 24 Jun. 0.0314 0.0273 0.0290
03:01-04:00, Sun., 24 Jun. 0.0299 0.0260 0.0278
02:01-03:00, Sun., 24 Jun. 0.0292 0.0246 0.0272
01:01-02:00, Sun., 24 Jun. 0.0286 0.0248 0.0271
00:01-01:00, Sun., 24 Jun. 0.0296 0.0260 0.0275
23:01-24:00, Sat., 23 Jun. 0.0292 0.0252 0.0273
22:01-23:00, Sat., 23 Jun. 0.0288 0.0262 0.0273
21:01-22:00, Sat., 23 Jun. 0.0300 0.0266 0.0280
20:01-21:00, Sat., 23 Jun. 0.0334 0.0272 0.0297
19:01-20:00, Sat., 23 Jun. 0.0395 0.0306 0.0347
18:01-19:00, Sat., 23 Jun. 0.0492 0.0370 0.0432
17:01-18:00, Sat., 23 Jun. 0.0492 0.0392 0.0438
16:01-17:00, Sat., 23 Jun. 0.0425 0.0365 0.0398
15:01-16:00, Sat., 23 Jun. 0.0408 0.0359 0.0381
14:01-15:00, Sat., 23 Jun. 0.0380 0.0292 0.0331
13:01-14:00, Sat., 23 Jun. 0.0333 0.0274 0.0306
12:01-13:00, Sat., 23 Jun. 0.0311 0.0269 0.0291
11:01-12:00, Sat., 23 Jun. 0.0309 0.0265 0.0283
10:01-11:00, Sat., 23 Jun. 0.0308 0.0265 0.0286
09:01-10:00, Sat., 23 Jun. 0.0305 0.0264 0.0283
08:01-09:00, Sat., 23 Jun. 0.0299 0.0264 0.0281
07:01-08:00, Sat., 23 Jun. 0.0301 0.0261 0.0281
06:01-07:00, Sat., 23 Jun. 0.0304 0.0267 0.0282
05:01-06:00, Sat., 23 Jun. 0.0302 0.0259 0.0284
04:01-05:00, Sat., 23 Jun. 0.0305 0.0265 0.0282
03:01-04:00, Sat., 23 Jun. 0.0300 0.0266 0.0284
02:01-03:00, Sat., 23 Jun. 0.0303 0.0262 0.0285
01:01-02:00, Sat., 23 Jun. 0.0304 0.0263 0.0284
00:01-01:00, Sat., 23 Jun. 0.0300 0.0266 0.0284
23:01-24:00, Fri., 22 Jun. 0.0294 0.0263 0.0279
22:01-23:00, Fri., 22 Jun. 0.0307 0.0258 0.0279
21:01-22:00, Fri., 22 Jun. 0.0304 0.0264 0.0279
20:01-21:00, Fri., 22 Jun. 0.0292 0.0254 0.0279
19:01-20:00, Fri., 22 Jun. 0.0296 0.0261 0.0279
18:01-19:00, Fri., 22 Jun. 0.0297 0.0254 0.0279
17:01-18:00, Fri., 22 Jun. 0.0307 0.0261 0.0279
16:01-17:00, Fri., 22 Jun. 0.0303 0.0253 0.0280
15:01-16:00, Fri., 22 Jun. 0.0298 0.0256 0.0277
14:01-15:00, Fri., 22 Jun. 0.0291 0.0255 0.0275
13:01-14:00, Fri., 22 Jun. 0.0297 0.0261 0.0278
12:01-13:00, Fri., 22 Jun. 0.0305 0.0259 0.0282
11:01-12:00, Fri., 22 Jun. 0.0295 0.0261 0.0278
10:01-11:00, Fri., 22 Jun. 0.0299 0.0262 0.0278
09:01-10:00, Fri., 22 Jun. 0.0295 0.0261 0.0276
08:01-09:00, Fri., 22 Jun. 0.0308 0.0263 0.0281
07:01-08:00, Fri., 22 Jun. 0.0309 0.0264 0.0287
06:01-07:00, Fri., 22 Jun. 0.0324 0.0277 0.0302
05:01-06:00, Fri., 22 Jun. 0.0331 0.0277 0.0304
04:01-05:00, Fri., 22 Jun. 0.0319 0.0280 0.0298
03:01-04:00, Fri., 22 Jun. 0.0312 0.0272 0.0291
02:01-03:00, Fri., 22 Jun. 0.0306 0.0273 0.0284
01:01-02:00, Fri., 22 Jun. 0.0298 0.0263 0.0278
00:01-01:00, Fri., 22 Jun. 0.0298 0.0261 0.0277
23:01-24:00, Thu., 21 Jun. 0.0300 0.0257 0.0278
22:01-23:00, Thu., 21 Jun. 0.0293 0.0263 0.0276
21:01-22:00, Thu., 21 Jun. 0.0297 0.0251 0.0276
20:01-21:00, Thu., 21 Jun. 0.0292 0.0255 0.0273
19:01-20:00, Thu., 21 Jun. 0.0293 0.0248 0.0274
18:01-19:00, Thu., 21 Jun. 0.0294 0.0251 0.0273
17:01-18:00, Thu., 21 Jun. 0.0303 0.0253 0.0272
16:01-17:00, Thu., 21 Jun. 0.0287 0.0255 0.0271
15:01-16:00, Thu., 21 Jun. 0.0290 0.0251 0.0272
14:01-15:00, Thu., 21 Jun. 0.0287 0.0251 0.0269
13:01-14:00, Thu., 21 Jun. 0.0296 0.0253 0.0271
12:01-13:00, Thu., 21 Jun. 0.0291 0.0254 0.0269
11:01-12:00, Thu., 21 Jun. 0.0286 0.0247 0.0270
10:01-11:00, Thu., 21 Jun. 0.0292 0.0258 0.0274
09:01-10:00, Thu., 21 Jun. 0.0284 0.0253 0.0271
08:01-09:00, Thu., 21 Jun. 0.0294 0.0258 0.0273
07:01-08:00, Thu., 21 Jun. 0.0287 0.0250 0.0270
06:01-07:00, Thu., 21 Jun. 0.0301 0.0260 0.0276
05:01-06:00, Thu., 21 Jun. 0.0332 0.0267 0.0297
04:01-05:00, Thu., 21 Jun. 0.0360 0.0301 0.0331
03:01-04:00, Thu., 21 Jun. 0.0326 0.0267 0.0295
02:01-03:00, Thu., 21 Jun. 0.0320 0.0276 0.0297
01:01-02:00, Thu., 21 Jun. 0.0296 0.0261 0.0278
00:01-01:00, Thu., 21 Jun. 0.0337 0.0277 0.0302
23:01-24:00, Wed., 20 Jun. 0.0440 0.0321 0.0372
22:01-23:00, Wed., 20 Jun. 0.0448 0.0351 0.0401
21:01-22:00, Wed., 20 Jun. 0.0357 0.0300 0.0324
20:01-21:00, Wed., 20 Jun. 0.0342 0.0283 0.0315
19:01-20:00, Wed., 20 Jun. 0.0334 0.0272 0.0298
18:01-19:00, Wed., 20 Jun. 0.0301 0.0258 0.0277
17:01-18:00, Wed., 20 Jun. 0.0293 0.0252 0.0271
16:01-17:00, Wed., 20 Jun. 0.0290 0.0251 0.0271
15:01-16:00, Wed., 20 Jun. 0.0295 0.0255 0.0277
14:01-15:00, Wed., 20 Jun. 0.0305 0.0267 0.0284
13:01-14:00, Wed., 20 Jun. 0.0298 0.0264 0.0286
12:01-13:00, Wed., 20 Jun. 0.0329 0.0275 0.0303
11:01-12:00, Wed., 20 Jun. 0.0360 0.0309 0.0336
10:01-11:00, Wed., 20 Jun. 0.0356 0.0291 0.0326
09:01-10:00, Wed., 20 Jun. 0.0344 0.0282 0.0313
08:01-09:00, Wed., 20 Jun. 0.0347 0.0314 0.0332
07:01-08:00, Wed., 20 Jun. 0.0355 0.0310 0.0333
06:01-07:00, Wed., 20 Jun. 0.0333 0.0280 0.0303
05:01-06:00, Wed., 20 Jun. 0.0342 0.0287 0.0313
04:01-05:00, Wed., 20 Jun. 0.0338 0.0277 0.0305
03:01-04:00, Wed., 20 Jun. 0.0307 0.0268 0.0288
02:01-03:00, Wed., 20 Jun. 0.0298 0.0257 0.0280
01:01-02:00, Wed., 20 Jun. 0.0289 0.0255 0.0274
00:01-01:00, Wed., 20 Jun. 0.0293 0.0251 0.0274
23:01-24:00, Tue., 19 Jun. 0.0301 0.0257 0.0275
22:01-23:00, Tue., 19 Jun. 0.0295 0.0253 0.0271
21:01-22:00, Tue., 19 Jun. 0.0301 0.0260 0.0275
20:01-21:00, Tue., 19 Jun. 0.0297 0.0260 0.0276
19:01-20:00, Tue., 19 Jun. 0.0298 0.0253 0.0273
18:01-19:00, Tue., 19 Jun. 0.0293 0.0255 0.0273
17:01-18:00, Tue., 19 Jun. 0.0293 0.0257 0.0272
16:01-17:00, Tue., 19 Jun. 0.0295 0.0263 0.0277
15:01-16:00, Tue., 19 Jun. 0.0309 0.0251 0.0275
14:01-15:00, Tue., 19 Jun. 0.0310 0.0256 0.0276
13:01-14:00, Tue., 19 Jun. 0.0286 0.0256 0.0274
12:01-13:00, Tue., 19 Jun. 0.0293 0.0246 0.0273
11:01-12:00, Tue., 19 Jun. 0.0295 0.0248 0.0274
10:01-11:00, Tue., 19 Jun. 0.0288 0.0250 0.0274
09:01-10:00, Tue., 19 Jun. 0.0290 0.0259 0.0273
08:01-09:00, Tue., 19 Jun. 0.0291 0.0260 0.0278
07:01-08:00, Tue., 19 Jun. 0.0313 0.0264 0.0284
06:01-07:00, Tue., 19 Jun. 0.0303 0.0253 0.0280
05:01-06:00, Tue., 19 Jun. 0.0300 0.0261 0.0281
04:01-05:00, Tue., 19 Jun. 0.0298 0.0252 0.0278
03:01-04:00, Tue., 19 Jun. 0.0292 0.0265 0.0277
02:01-03:00, Tue., 19 Jun. 0.0295 0.0257 0.0277
01:01-02:00, Tue., 19 Jun. 0.0296 0.0261 0.0277
00:01-01:00, Tue., 19 Jun. 0.0294 0.0255 0.0277
23:01-24:00, Mon., 18 Jun. 0.0295 0.0257 0.0275
22:01-23:00, Mon., 18 Jun. 0.0300 0.0261 0.0276
21:01-22:00, Mon., 18 Jun. 0.0296 0.0256 0.0277
20:01-21:00, Mon., 18 Jun. 0.0302 0.0266 0.0284
19:01-20:00, Mon., 18 Jun. 0.0320 0.0273 0.0296
18:01-19:00, Mon., 18 Jun. 0.0316 0.0269 0.0291
17:01-18:00, Mon., 18 Jun. 0.0290 0.0256 0.0276
16:01-17:00, Mon., 18 Jun. 0.0307 0.0259 0.0284
15:01-16:00, Mon., 18 Jun. 0.0318 0.0285 0.0305
14:01-15:00, Mon., 18 Jun. 0.0326 0.0271 0.0295
13:01-14:00, Mon., 18 Jun. 0.0297 0.0263 0.0280
12:01-13:00, Mon., 18 Jun. 0.0293 0.0256 0.0281
11:01-12:00, Mon., 18 Jun. 0.0300 0.0260 0.0277
10:01-11:00, Mon., 18 Jun. 0.0295 0.0254 0.0276
09:01-10:00, Mon., 18 Jun. 0.0294 0.0258 0.0277
08:01-09:00, Mon., 18 Jun. 0.0309 0.0265 0.0284
07:01-08:00, Mon., 18 Jun. 0.0312 0.0271 0.0288
06:01-07:00, Mon., 18 Jun. 0.0301 0.0268 0.0285
05:01-06:00, Mon., 18 Jun. 0.0311 0.0264 0.0286
04:01-05:00, Mon., 18 Jun. 0.0297 0.0249 0.0282
03:01-04:00, Mon., 18 Jun. 0.0305 0.0264 0.0286
02:01-03:00, Mon., 18 Jun. 0.0307 0.0268 0.0287
01:01-02:00, Mon., 18 Jun. 0.0307 0.0267 0.0285
00:01-01:00, Mon., 18 Jun. 0.0301 0.0259 0.0282
23:01-24:00, Sun., 17 Jun. 0.0292 0.0252 0.0273
22:01-23:00, Sun., 17 Jun. 0.0289 0.0249 0.0274
21:01-22:00, Sun., 17 Jun. 0.0289 0.0257 0.0272
20:01-21:00, Sun., 17 Jun. 0.0290 0.0243 0.0273
19:01-20:00, Sun., 17 Jun. 0.0297 0.0254 0.0271
18:01-19:00, Sun., 17 Jun. 0.0295 0.0249 0.0270
17:01-18:00, Sun., 17 Jun. 0.0296 0.0250 0.0270
16:01-17:00, Sun., 17 Jun. 0.0300 0.0255 0.0270
15:01-16:00, Sun., 17 Jun. 0.0289 0.0257 0.0272
14:01-15:00, Sun., 17 Jun. 0.0291 0.0257 0.0272
13:01-14:00, Sun., 17 Jun. 0.0287 0.0253 0.0268
12:01-13:00, Sun., 17 Jun. 0.0290 0.0252 0.0269
11:01-12:00, Sun., 17 Jun. 0.0292 0.0248 0.0269
10:01-11:00, Sun., 17 Jun. 0.0293 0.0251 0.0270
09:01-10:00, Sun., 17 Jun. 0.0293 0.0245 0.0271
08:01-09:00, Sun., 17 Jun. 0.0287 0.0254 0.0271
07:01-08:00, Sun., 17 Jun. 0.0285 0.0250 0.0269
06:01-07:00, Sun., 17 Jun. 0.0293 0.0247 0.0272
05:01-06:00, Sun., 17 Jun. 0.0300 0.0253 0.0273
04:01-05:00, Sun., 17 Jun. 0.0295 0.0252 0.0270
03:01-04:00, Sun., 17 Jun. 0.0289 0.0254 0.0270
02:01-03:00, Sun., 17 Jun. 0.0293 0.0249 0.0269
01:01-02:00, Sun., 17 Jun. 0.0289 0.0258 0.0271
00:01-01:00, Sun., 17 Jun. 0.0298 0.0251 0.0272
23:01-24:00, Sat., 16 Jun. 0.0289 0.0258 0.0272
22:01-23:00, Sat., 16 Jun. 0.0291 0.0245 0.0268
21:01-22:00, Sat., 16 Jun. 0.0289 0.0244 0.0268
20:01-21:00, Sat., 16 Jun. 0.0295 0.0253 0.0269
19:01-20:00, Sat., 16 Jun. 0.0288 0.0253 0.0272
18:01-19:00, Sat., 16 Jun. 0.0287 0.0249 0.0270
17:01-18:00, Sat., 16 Jun. 0.0294 0.0249 0.0271
16:01-17:00, Sat., 16 Jun. 0.0284 0.0255 0.0269
15:01-16:00, Sat., 16 Jun. 0.0285 0.0252 0.0268
14:01-15:00, Sat., 16 Jun. 0.0288 0.0248 0.0268
13:01-14:00, Sat., 16 Jun. 0.0286 0.0255 0.0269
12:01-13:00, Sat., 16 Jun. 0.0290 0.0245 0.0268
11:01-12:00, Sat., 16 Jun. 0.0296 0.0253 0.0271
10:01-11:00, Sat., 16 Jun. 0.0285 0.0250 0.0269
09:01-10:00, Sat., 16 Jun. 0.0295 0.0254 0.0273
08:01-09:00, Sat., 16 Jun. 0.0296 0.0256 0.0276
07:01-08:00, Sat., 16 Jun. 0.0303 0.0260 0.0280
06:01-07:00, Sat., 16 Jun. 0.0298 0.0261 0.0278
05:01-06:00, Sat., 16 Jun. 0.0313 0.0267 0.0286
04:01-05:00, Sat., 16 Jun. 0.0325 0.0289 0.0305
03:01-04:00, Sat., 16 Jun. 0.0343 0.0293 0.0316
02:01-03:00, Sat., 16 Jun. 0.0330 0.0259 0.0286
01:01-02:00, Sat., 16 Jun. 0.0296 0.0260 0.0277
00:01-01:00, Sat., 16 Jun. 0.0304 0.0262 0.0278
23:01-24:00, Fri., 15 Jun. 0.0295 0.0254 0.0277
22:01-23:00, Fri., 15 Jun. 0.0290 0.0248 0.0274
21:01-22:00, Fri., 15 Jun. 0.0311 0.0265 0.0287
20:01-21:00, Fri., 15 Jun. 0.0314 0.0263 0.0287
19:01-20:00, Fri., 15 Jun. 0.0313 0.0270 0.0285
18:01-19:00, Fri., 15 Jun. 0.0335 0.0268 0.0302
17:01-18:00, Fri., 15 Jun. 0.0348 0.0303 0.0325
16:01-17:00, Fri., 15 Jun. 0.0352 0.0304 0.0326
15:01-16:00, Fri., 15 Jun. 0.0375 0.0304 0.0343
14:01-15:00, Fri., 15 Jun. 0.0382 0.0319 0.0344
13:01-14:00, Fri., 15 Jun. 0.0352 0.0311 0.0331
12:01-13:00, Fri., 15 Jun. 0.0369 0.0312 0.0345
11:01-12:00, Fri., 15 Jun. 0.0365 0.0307 0.0341
10:01-11:00, Fri., 15 Jun. 0.0341 0.0262 0.0288
09:01-10:00, Fri., 15 Jun. 0.0292 0.0260 0.0276
08:01-09:00, Fri., 15 Jun. 0.0300 0.0263 0.0279
07:01-08:00, Fri., 15 Jun. 0.0294 0.0257 0.0277
06:01-07:00, Fri., 15 Jun. 0.0293 0.0259 0.0277
05:01-06:00, Fri., 15 Jun. 0.0297 0.0260 0.0280
04:01-05:00, Fri., 15 Jun. 0.0296 0.0259 0.0278
03:01-04:00, Fri., 15 Jun. 0.0310 0.0269 0.0284
02:01-03:00, Fri., 15 Jun. 0.0312 0.0262 0.0286
01:01-02:00, Fri., 15 Jun. 0.0306 0.0252 0.0275
00:01-01:00, Fri., 15 Jun. 0.0293 0.0251 0.0273
23:01-24:00, Thu., 14 Jun. 0.0300 0.0256 0.0274
22:01-23:00, Thu., 14 Jun. 0.0303 0.0254 0.0273
21:01-22:00, Thu., 14 Jun. 0.0291 0.0258 0.0275
20:01-21:00, Thu., 14 Jun. 0.0293 0.0251 0.0275