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 10:00 to 13:00 on Tuesday, February 6,2018 Hachioji
From 13:00 to 16:00 on Tuesday, February 6,2018 Kodaira
From 10:00 to 13:00 on Wednesday, February 7,2018 Chofu
From 13:00 to 16:00 on Wednesday, February 7,2018 Ota
From 10:00 to 13:00 on Thursday, February 8,2018 Adachi
From 13:00 to 16:00 on Thursday, February 8,2018 Edogawa
From 10:00 to 13:00 on Friday, February 9,2018 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
13:01-14:00, Tue., 20 Feb. 0.0320 0.0281 0.0297
12:01-13:00, Tue., 20 Feb. 0.0308 0.0277 0.0294
11:01-12:00, Tue., 20 Feb. 0.0318 0.0278 0.0296
10:01-11:00, Tue., 20 Feb. 0.0321 0.0280 0.0299
09:01-10:00, Tue., 20 Feb. 0.0331 0.0281 0.0300
08:01-09:00, Tue., 20 Feb. 0.0326 0.0280 0.0305
07:01-08:00, Tue., 20 Feb. 0.0315 0.0283 0.0300
06:01-07:00, Tue., 20 Feb. 0.0314 0.0275 0.0298
05:01-06:00, Tue., 20 Feb. 0.0321 0.0274 0.0297
04:01-05:00, Tue., 20 Feb. 0.0315 0.0271 0.0294
03:01-04:00, Tue., 20 Feb. 0.0316 0.0276 0.0295
02:01-03:00, Tue., 20 Feb. 0.0317 0.0276 0.0299
01:01-02:00, Tue., 20 Feb. 0.0327 0.0280 0.0299
00:01-01:00, Tue., 20 Feb. 0.0321 0.0279 0.0300
23:01-24:00, Mon., 19 Feb. 0.0324 0.0282 0.0298
22:01-23:00, Mon., 19 Feb. 0.0308 0.0277 0.0295
21:01-22:00, Mon., 19 Feb. 0.0307 0.0271 0.0291
20:01-21:00, Mon., 19 Feb. 0.0306 0.0273 0.0291
19:01-20:00, Mon., 19 Feb. 0.0310 0.0272 0.0289
18:01-19:00, Mon., 19 Feb. 0.0316 0.0266 0.0288
17:01-18:00, Mon., 19 Feb. 0.0308 0.0270 0.0289
16:01-17:00, Mon., 19 Feb. 0.0314 0.0271 0.0290
15:01-16:00, Mon., 19 Feb. 0.0307 0.0272 0.0288
14:01-15:00, Mon., 19 Feb. 0.0307 0.0269 0.0290
13:01-14:00, Mon., 19 Feb. 0.0313 0.0274 0.0290
12:01-13:00, Mon., 19 Feb. 0.0317 0.0276 0.0295
11:01-12:00, Mon., 19 Feb. 0.0318 0.0277 0.0296
10:01-11:00, Mon., 19 Feb. 0.0322 0.0279 0.0299
09:01-10:00, Mon., 19 Feb. 0.0321 0.0279 0.0299
08:01-09:00, Mon., 19 Feb. 0.0321 0.0282 0.0300
07:01-08:00, Mon., 19 Feb. 0.0326 0.0281 0.0301
06:01-07:00, Mon., 19 Feb. 0.0314 0.0283 0.0297
05:01-06:00, Mon., 19 Feb. 0.0323 0.0275 0.0297
04:01-05:00, Mon., 19 Feb. 0.0310 0.0279 0.0294
03:01-04:00, Mon., 19 Feb. 0.0309 0.0273 0.0292
02:01-03:00, Mon., 19 Feb. 0.0303 0.0269 0.0290
01:01-02:00, Mon., 19 Feb. 0.0311 0.0274 0.0291
00:01-01:00, Mon., 19 Feb. 0.0310 0.0270 0.0290
23:01-24:00, Sun., 18 Feb. 0.0315 0.0269 0.0290
22:01-23:00, Sun., 18 Feb. 0.0308 0.0273 0.0289
21:01-22:00, Sun., 18 Feb. 0.0307 0.0275 0.0289
20:01-21:00, Sun., 18 Feb. 0.0310 0.0271 0.0289
19:01-20:00, Sun., 18 Feb. 0.0307 0.0265 0.0288
18:01-19:00, Sun., 18 Feb. 0.0323 0.0268 0.0289
17:01-18:00, Sun., 18 Feb. 0.0316 0.0270 0.0286
16:01-17:00, Sun., 18 Feb. 0.0303 0.0264 0.0286
15:01-16:00, Sun., 18 Feb. 0.0315 0.0261 0.0285
14:01-15:00, Sun., 18 Feb. 0.0307 0.0265 0.0289
13:01-14:00, Sun., 18 Feb. 0.0313 0.0272 0.0289
12:01-13:00, Sun., 18 Feb. 0.0314 0.0273 0.0292
11:01-12:00, Sun., 18 Feb. 0.0311 0.0266 0.0291
10:01-11:00, Sun., 18 Feb. 0.0310 0.0271 0.0293
09:01-10:00, Sun., 18 Feb. 0.0306 0.0267 0.0291
08:01-09:00, Sun., 18 Feb. 0.0318 0.0265 0.0292
07:01-08:00, Sun., 18 Feb. 0.0314 0.0262 0.0289
06:01-07:00, Sun., 18 Feb. 0.0320 0.0271 0.0291
05:01-06:00, Sun., 18 Feb. 0.0313 0.0261 0.0292
04:01-05:00, Sun., 18 Feb. 0.0308 0.0273 0.0289
03:01-04:00, Sun., 18 Feb. 0.0312 0.0269 0.0291
02:01-03:00, Sun., 18 Feb. 0.0312 0.0274 0.0292
01:01-02:00, Sun., 18 Feb. 0.0313 0.0274 0.0293
00:01-01:00, Sun., 18 Feb. 0.0312 0.0270 0.0293
23:01-24:00, Sat., 17 Feb. 0.0314 0.0271 0.0291
22:01-23:00, Sat., 17 Feb. 0.0312 0.0276 0.0293
21:01-22:00, Sat., 17 Feb. 0.0312 0.0279 0.0294
20:01-21:00, Sat., 17 Feb. 0.0317 0.0273 0.0296
19:01-20:00, Sat., 17 Feb. 0.0315 0.0285 0.0297
18:01-19:00, Sat., 17 Feb. 0.0317 0.0281 0.0297
17:01-18:00, Sat., 17 Feb. 0.0318 0.0279 0.0296
16:01-17:00, Sat., 17 Feb. 0.0317 0.0285 0.0298
15:01-16:00, Sat., 17 Feb. 0.0310 0.0276 0.0293
14:01-15:00, Sat., 17 Feb. 0.0311 0.0270 0.0294
13:01-14:00, Sat., 17 Feb. 0.0313 0.0272 0.0290
12:01-13:00, Sat., 17 Feb. 0.0311 0.0269 0.0290
11:01-12:00, Sat., 17 Feb. 0.0310 0.0281 0.0293
10:01-11:00, Sat., 17 Feb. 0.0316 0.0264 0.0291
09:01-10:00, Sat., 17 Feb. 0.0314 0.0274 0.0292
08:01-09:00, Sat., 17 Feb. 0.0315 0.0273 0.0292
07:01-08:00, Sat., 17 Feb. 0.0309 0.0268 0.0292
06:01-07:00, Sat., 17 Feb. 0.0302 0.0266 0.0290
05:01-06:00, Sat., 17 Feb. 0.0315 0.0271 0.0290
04:01-05:00, Sat., 17 Feb. 0.0311 0.0264 0.0288
03:01-04:00, Sat., 17 Feb. 0.0312 0.0272 0.0288
02:01-03:00, Sat., 17 Feb. 0.0306 0.0271 0.0290
01:01-02:00, Sat., 17 Feb. 0.0306 0.0269 0.0287
00:01-01:00, Sat., 17 Feb. 0.0302 0.0271 0.0286
23:01-24:00, Fri., 16 Feb. 0.0301 0.0266 0.0284
22:01-23:00, Fri., 16 Feb. 0.0308 0.0266 0.0285
21:01-22:00, Fri., 16 Feb. 0.0306 0.0271 0.0287
20:01-21:00, Fri., 16 Feb. 0.0307 0.0271 0.0287
19:01-20:00, Fri., 16 Feb. 0.0313 0.0265 0.0287
18:01-19:00, Fri., 16 Feb. 0.0305 0.0272 0.0285
17:01-18:00, Fri., 16 Feb. 0.0304 0.0261 0.0286
16:01-17:00, Fri., 16 Feb. 0.0308 0.0265 0.0286
15:01-16:00, Fri., 16 Feb. 0.0310 0.0261 0.0286
14:01-15:00, Fri., 16 Feb. 0.0304 0.0271 0.0288
13:01-14:00, Fri., 16 Feb. 0.0306 0.0270 0.0289
12:01-13:00, Fri., 16 Feb. 0.0314 0.0272 0.0289
11:01-12:00, Fri., 16 Feb. 0.0312 0.0271 0.0292
10:01-11:00, Fri., 16 Feb. 0.0311 0.0273 0.0293
09:01-10:00, Fri., 16 Feb. 0.0306 0.0271 0.0291
08:01-09:00, Fri., 16 Feb. 0.0310 0.0270 0.0290
07:01-08:00, Fri., 16 Feb. 0.0313 0.0277 0.0293
06:01-07:00, Fri., 16 Feb. 0.0317 0.0275 0.0293
05:01-06:00, Fri., 16 Feb. 0.0310 0.0276 0.0293
04:01-05:00, Fri., 16 Feb. 0.0313 0.0274 0.0291
03:01-04:00, Fri., 16 Feb. 0.0316 0.0273 0.0292
02:01-03:00, Fri., 16 Feb. 0.0313 0.0279 0.0294
01:01-02:00, Fri., 16 Feb. 0.0306 0.0274 0.0293
00:01-01:00, Fri., 16 Feb. 0.0306 0.0268 0.0287
23:01-24:00, Thu., 15 Feb. 0.0314 0.0269 0.0289
22:01-23:00, Thu., 15 Feb. 0.0312 0.0272 0.0288
21:01-22:00, Thu., 15 Feb. 0.0305 0.0272 0.0290
20:01-21:00, Thu., 15 Feb. 0.0308 0.0258 0.0288
19:01-20:00, Thu., 15 Feb. 0.0314 0.0270 0.0291
18:01-19:00, Thu., 15 Feb. 0.0309 0.0266 0.0288
17:01-18:00, Thu., 15 Feb. 0.0302 0.0264 0.0285
16:01-17:00, Thu., 15 Feb. 0.0305 0.0271 0.0290
15:01-16:00, Thu., 15 Feb. 0.0313 0.0270 0.0292
14:01-15:00, Thu., 15 Feb. 0.0309 0.0272 0.0291
13:01-14:00, Thu., 15 Feb. 0.0308 0.0275 0.0293
12:01-13:00, Thu., 15 Feb. 0.0318 0.0270 0.0294
11:01-12:00, Thu., 15 Feb. 0.0309 0.0279 0.0295
10:01-11:00, Thu., 15 Feb. 0.0315 0.0269 0.0296
09:01-10:00, Thu., 15 Feb. 0.0313 0.0275 0.0293
08:01-09:00, Thu., 15 Feb. 0.0325 0.0279 0.0295
07:01-08:00, Thu., 15 Feb. 0.0316 0.0282 0.0299
06:01-07:00, Thu., 15 Feb. 0.0315 0.0277 0.0298
05:01-06:00, Thu., 15 Feb. 0.0318 0.0278 0.0297
04:01-05:00, Thu., 15 Feb. 0.0307 0.0277 0.0292
03:01-04:00, Thu., 15 Feb. 0.0318 0.0273 0.0291
02:01-03:00, Thu., 15 Feb. 0.0304 0.0273 0.0291
01:01-02:00, Thu., 15 Feb. 0.0317 0.0273 0.0292
00:01-01:00, Thu., 15 Feb. 0.0315 0.0274 0.0289
23:01-24:00, Wed., 14 Feb. 0.0315 0.0267 0.0290
22:01-23:00, Wed., 14 Feb. 0.0313 0.0269 0.0289
21:01-22:00, Wed., 14 Feb. 0.0306 0.0268 0.0290
20:01-21:00, Wed., 14 Feb. 0.0314 0.0262 0.0286
19:01-20:00, Wed., 14 Feb. 0.0305 0.0269 0.0286
18:01-19:00, Wed., 14 Feb. 0.0306 0.0271 0.0285
17:01-18:00, Wed., 14 Feb. 0.0302 0.0260 0.0282
16:01-17:00, Wed., 14 Feb. 0.0310 0.0268 0.0284
15:01-16:00, Wed., 14 Feb. 0.0302 0.0269 0.0287
14:01-15:00, Wed., 14 Feb. 0.0311 0.0272 0.0289
13:01-14:00, Wed., 14 Feb. 0.0306 0.0267 0.0287
12:01-13:00, Wed., 14 Feb. 0.0304 0.0272 0.0289
11:01-12:00, Wed., 14 Feb. 0.0311 0.0267 0.0290
10:01-11:00, Wed., 14 Feb. 0.0313 0.0273 0.0293
09:01-10:00, Wed., 14 Feb. 0.0318 0.0286 0.0301
08:01-09:00, Wed., 14 Feb. 0.0331 0.0285 0.0307
07:01-08:00, Wed., 14 Feb. 0.0329 0.0293 0.0311
06:01-07:00, Wed., 14 Feb. 0.0331 0.0296 0.0311
05:01-06:00, Wed., 14 Feb. 0.0333 0.0289 0.0310
04:01-05:00, Wed., 14 Feb. 0.0331 0.0290 0.0311
03:01-04:00, Wed., 14 Feb. 0.0331 0.0287 0.0304
02:01-03:00, Wed., 14 Feb. 0.0326 0.0276 0.0298
01:01-02:00, Wed., 14 Feb. 0.0312 0.0274 0.0292
00:01-01:00, Wed., 14 Feb. 0.0310 0.0274 0.0291
23:01-24:00, Tue., 13 Feb. 0.0310 0.0276 0.0290
22:01-23:00, Tue., 13 Feb. 0.0304 0.0272 0.0291
21:01-22:00, Tue., 13 Feb. 0.0307 0.0272 0.0288
20:01-21:00, Tue., 13 Feb. 0.0305 0.0274 0.0290
19:01-20:00, Tue., 13 Feb. 0.0304 0.0266 0.0287
18:01-19:00, Tue., 13 Feb. 0.0313 0.0272 0.0292
17:01-18:00, Tue., 13 Feb. 0.0309 0.0268 0.0289
16:01-17:00, Tue., 13 Feb. 0.0311 0.0266 0.0291
15:01-16:00, Tue., 13 Feb. 0.0309 0.0267 0.0290
14:01-15:00, Tue., 13 Feb. 0.0309 0.0266 0.0288
13:01-14:00, Tue., 13 Feb. 0.0318 0.0264 0.0289
12:01-13:00, Tue., 13 Feb. 0.0308 0.0270 0.0287
11:01-12:00, Tue., 13 Feb. 0.0303 0.0265 0.0288
10:01-11:00, Tue., 13 Feb. 0.0305 0.0260 0.0287
09:01-10:00, Tue., 13 Feb. 0.0313 0.0277 0.0293
08:01-09:00, Tue., 13 Feb. 0.0321 0.0274 0.0299
07:01-08:00, Tue., 13 Feb. 0.0332 0.0270 0.0299
06:01-07:00, Tue., 13 Feb. 0.0324 0.0276 0.0300
05:01-06:00, Tue., 13 Feb. 0.0331 0.0268 0.0296
04:01-05:00, Tue., 13 Feb. 0.0317 0.0275 0.0297
03:01-04:00, Tue., 13 Feb. 0.0313 0.0269 0.0293
02:01-03:00, Tue., 13 Feb. 0.0311 0.0270 0.0293
01:01-02:00, Tue., 13 Feb. 0.0314 0.0265 0.0292
00:01-01:00, Tue., 13 Feb. 0.0315 0.0275 0.0295
23:01-24:00, Mon., 12 Feb. 0.0310 0.0273 0.0292
22:01-23:00, Mon., 12 Feb. 0.0305 0.0272 0.0291
21:01-22:00, Mon., 12 Feb. 0.0312 0.0266 0.0290
20:01-21:00, Mon., 12 Feb. 0.0303 0.0269 0.0288
19:01-20:00, Mon., 12 Feb. 0.0313 0.0268 0.0290
18:01-19:00, Mon., 12 Feb. 0.0315 0.0270 0.0289
17:01-18:00, Mon., 12 Feb. 0.0310 0.0265 0.0288
16:01-17:00, Mon., 12 Feb. 0.0305 0.0272 0.0288
15:01-16:00, Mon., 12 Feb. 0.0315 0.0267 0.0290
14:01-15:00, Mon., 12 Feb. 0.0312 0.0275 0.0292
13:01-14:00, Mon., 12 Feb. 0.0314 0.0269 0.0290
12:01-13:00, Mon., 12 Feb. 0.0311 0.0272 0.0290
11:01-12:00, Mon., 12 Feb. 0.0311 0.0267 0.0289
10:01-11:00, Mon., 12 Feb. 0.0308 0.0269 0.0290
09:01-10:00, Mon., 12 Feb. 0.0307 0.0263 0.0287
08:01-09:00, Mon., 12 Feb. 0.0309 0.0273 0.0292
07:01-08:00, Mon., 12 Feb. 0.0308 0.0273 0.0288
06:01-07:00, Mon., 12 Feb. 0.0311 0.0273 0.0290
05:01-06:00, Mon., 12 Feb. 0.0319 0.0260 0.0289
04:01-05:00, Mon., 12 Feb. 0.0309 0.0268 0.0289
03:01-04:00, Mon., 12 Feb. 0.0315 0.0276 0.0290
02:01-03:00, Mon., 12 Feb. 0.0312 0.0268 0.0290
01:01-02:00, Mon., 12 Feb. 0.0312 0.0266 0.0289
00:01-01:00, Mon., 12 Feb. 0.0310 0.0272 0.0289
23:01-24:00, Sun., 11 Feb. 0.0310 0.0270 0.0289
22:01-23:00, Sun., 11 Feb. 0.0313 0.0267 0.0287
21:01-22:00, Sun., 11 Feb. 0.0305 0.0267 0.0288
20:01-21:00, Sun., 11 Feb. 0.0307 0.0272 0.0288
19:01-20:00, Sun., 11 Feb. 0.0304 0.0271 0.0286
18:01-19:00, Sun., 11 Feb. 0.0306 0.0267 0.0286
17:01-18:00, Sun., 11 Feb. 0.0311 0.0270 0.0287
16:01-17:00, Sun., 11 Feb. 0.0306 0.0269 0.0289
15:01-16:00, Sun., 11 Feb. 0.0307 0.0275 0.0290
14:01-15:00, Sun., 11 Feb. 0.0306 0.0261 0.0290
13:01-14:00, Sun., 11 Feb. 0.0310 0.0267 0.0288
12:01-13:00, Sun., 11 Feb. 0.0314 0.0275 0.0290
11:01-12:00, Sun., 11 Feb. 0.0320 0.0272 0.0295
10:01-11:00, Sun., 11 Feb. 0.0311 0.0272 0.0295
09:01-10:00, Sun., 11 Feb. 0.0328 0.0282 0.0301
08:01-09:00, Sun., 11 Feb. 0.0326 0.0285 0.0302
07:01-08:00, Sun., 11 Feb. 0.0325 0.0286 0.0306
06:01-07:00, Sun., 11 Feb. 0.0336 0.0287 0.0305
05:01-06:00, Sun., 11 Feb. 0.0318 0.0286 0.0301
04:01-05:00, Sun., 11 Feb. 0.0314 0.0276 0.0298
03:01-04:00, Sun., 11 Feb. 0.0319 0.0281 0.0299
02:01-03:00, Sun., 11 Feb. 0.0328 0.0281 0.0300
01:01-02:00, Sun., 11 Feb. 0.0312 0.0281 0.0296
00:01-01:00, Sun., 11 Feb. 0.0315 0.0277 0.0296
23:01-24:00, Sat., 10 Feb. 0.0320 0.0278 0.0299
22:01-23:00, Sat., 10 Feb. 0.0343 0.0292 0.0319
21:01-22:00, Sat., 10 Feb. 0.0347 0.0279 0.0307
20:01-21:00, Sat., 10 Feb. 0.0310 0.0273 0.0292
19:01-20:00, Sat., 10 Feb. 0.0306 0.0264 0.0287
18:01-19:00, Sat., 10 Feb. 0.0302 0.0270 0.0284
17:01-18:00, Sat., 10 Feb. 0.0308 0.0262 0.0285
16:01-17:00, Sat., 10 Feb. 0.0313 0.0260 0.0285
15:01-16:00, Sat., 10 Feb. 0.0302 0.0267 0.0286
14:01-15:00, Sat., 10 Feb. 0.0314 0.0263 0.0287