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.

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, Fri., 13 Feb. 0.0303 0.0258 0.0280
18:01-19:00, Fri., 13 Feb. 0.0302 0.0260 0.0277
17:01-18:00, Fri., 13 Feb. 0.0299 0.0249 0.0276
16:01-17:00, Fri., 13 Feb. 0.0298 0.0256 0.0279
15:01-16:00, Fri., 13 Feb. 0.0301 0.0262 0.0282
14:01-15:00, Fri., 13 Feb. 0.0308 0.0258 0.0283
13:01-14:00, Fri., 13 Feb. 0.0308 0.0260 0.0284
12:01-13:00, Fri., 13 Feb. 0.0309 0.0264 0.0284
11:01-12:00, Fri., 13 Feb. 0.0311 0.0263 0.0290
10:01-11:00, Fri., 13 Feb. 0.0317 0.0268 0.0292
09:01-10:00, Fri., 13 Feb. 0.0319 0.0273 0.0294
08:01-09:00, Fri., 13 Feb. 0.0325 0.0281 0.0304
07:01-08:00, Fri., 13 Feb. 0.0334 0.0290 0.0313
06:01-07:00, Fri., 13 Feb. 0.0332 0.0288 0.0308
05:01-06:00, Fri., 13 Feb. 0.0324 0.0286 0.0303
04:01-05:00, Fri., 13 Feb. 0.0322 0.0286 0.0305
03:01-04:00, Fri., 13 Feb. 0.0327 0.0280 0.0304
02:01-03:00, Fri., 13 Feb. 0.0318 0.0278 0.0303
01:01-02:00, Fri., 13 Feb. 0.0330 0.0287 0.0302
00:01-01:00, Fri., 13 Feb. 0.0321 0.0279 0.0297
23:01-24:00, Thu., 12 Feb. 0.0315 0.0276 0.0294
22:01-23:00, Thu., 12 Feb. 0.0315 0.0276 0.0295
21:01-22:00, Thu., 12 Feb. 0.0313 0.0264 0.0287
20:01-21:00, Thu., 12 Feb. 0.0297 0.0265 0.0283
19:01-20:00, Thu., 12 Feb. 0.0298 0.0259 0.0278
18:01-19:00, Thu., 12 Feb. 0.0294 0.0256 0.0277
17:01-18:00, Thu., 12 Feb. 0.0300 0.0255 0.0278
16:01-17:00, Thu., 12 Feb. 0.0298 0.0252 0.0277
15:01-16:00, Thu., 12 Feb. 0.0299 0.0259 0.0279
14:01-15:00, Thu., 12 Feb. 0.0307 0.0259 0.0282
13:01-14:00, Thu., 12 Feb. 0.0301 0.0262 0.0283
12:01-13:00, Thu., 12 Feb. 0.0302 0.0267 0.0283
11:01-12:00, Thu., 12 Feb. 0.0303 0.0251 0.0279
10:01-11:00, Thu., 12 Feb. 0.0303 0.0263 0.0280
09:01-10:00, Thu., 12 Feb. 0.0310 0.0263 0.0284
08:01-09:00, Thu., 12 Feb. 0.0301 0.0262 0.0281
07:01-08:00, Thu., 12 Feb. 0.0306 0.0255 0.0280
06:01-07:00, Thu., 12 Feb. 0.0301 0.0257 0.0279
05:01-06:00, Thu., 12 Feb. 0.0299 0.0259 0.0281
04:01-05:00, Thu., 12 Feb. 0.0304 0.0262 0.0282
03:01-04:00, Thu., 12 Feb. 0.0307 0.0259 0.0283
02:01-03:00, Thu., 12 Feb. 0.0308 0.0263 0.0281
01:01-02:00, Thu., 12 Feb. 0.0304 0.0261 0.0283
00:01-01:00, Thu., 12 Feb. 0.0311 0.0270 0.0292
23:01-24:00, Wed., 11 Feb. 0.0308 0.0257 0.0280
22:01-23:00, Wed., 11 Feb. 0.0299 0.0252 0.0275
21:01-22:00, Wed., 11 Feb. 0.0295 0.0254 0.0276
20:01-21:00, Wed., 11 Feb. 0.0296 0.0246 0.0274
19:01-20:00, Wed., 11 Feb. 0.0301 0.0248 0.0275
18:01-19:00, Wed., 11 Feb. 0.0308 0.0260 0.0284
17:01-18:00, Wed., 11 Feb. 0.0315 0.0279 0.0293
16:01-17:00, Wed., 11 Feb. 0.0319 0.0277 0.0293
15:01-16:00, Wed., 11 Feb. 0.0310 0.0262 0.0291
14:01-15:00, Wed., 11 Feb. 0.0325 0.0279 0.0299
13:01-14:00, Wed., 11 Feb. 0.0359 0.0300 0.0325
12:01-13:00, Wed., 11 Feb. 0.0465 0.0349 0.0407
11:01-12:00, Wed., 11 Feb. 0.0482 0.0401 0.0449
10:01-11:00, Wed., 11 Feb. 0.0466 0.0365 0.0419
09:01-10:00, Wed., 11 Feb. 0.0419 0.0355 0.0386
08:01-09:00, Wed., 11 Feb. 0.0435 0.0373 0.0404
07:01-08:00, Wed., 11 Feb. 0.0452 0.0350 0.0396
06:01-07:00, Wed., 11 Feb. 0.0364 0.0305 0.0337
05:01-06:00, Wed., 11 Feb. 0.0343 0.0291 0.0316
04:01-05:00, Wed., 11 Feb. 0.0320 0.0282 0.0303
03:01-04:00, Wed., 11 Feb. 0.0320 0.0279 0.0302
02:01-03:00, Wed., 11 Feb. 0.0316 0.0275 0.0296
01:01-02:00, Wed., 11 Feb. 0.0315 0.0269 0.0297
00:01-01:00, Wed., 11 Feb. 0.0315 0.0275 0.0294
23:01-24:00, Tue., 10 Feb. 0.0321 0.0271 0.0294
22:01-23:00, Tue., 10 Feb. 0.0313 0.0269 0.0290
21:01-22:00, Tue., 10 Feb. 0.0301 0.0263 0.0282
20:01-21:00, Tue., 10 Feb. 0.0301 0.0263 0.0280
19:01-20:00, Tue., 10 Feb. 0.0298 0.0259 0.0279
18:01-19:00, Tue., 10 Feb. 0.0298 0.0260 0.0278
17:01-18:00, Tue., 10 Feb. 0.0295 0.0255 0.0277
16:01-17:00, Tue., 10 Feb. 0.0296 0.0243 0.0275
15:01-16:00, Tue., 10 Feb. 0.0297 0.0252 0.0276
14:01-15:00, Tue., 10 Feb. 0.0300 0.0252 0.0276
13:01-14:00, Tue., 10 Feb. 0.0301 0.0260 0.0278
12:01-13:00, Tue., 10 Feb. 0.0303 0.0256 0.0279
11:01-12:00, Tue., 10 Feb. 0.0297 0.0263 0.0281
10:01-11:00, Tue., 10 Feb. 0.0305 0.0252 0.0282
09:01-10:00, Tue., 10 Feb. 0.0302 0.0258 0.0283
08:01-09:00, Tue., 10 Feb. 0.0309 0.0269 0.0287
07:01-08:00, Tue., 10 Feb. 0.0311 0.0271 0.0295
06:01-07:00, Tue., 10 Feb. 0.0325 0.0280 0.0303
05:01-06:00, Tue., 10 Feb. 0.0329 0.0275 0.0302
04:01-05:00, Tue., 10 Feb. 0.0335 0.0283 0.0305
03:01-04:00, Tue., 10 Feb. 0.0318 0.0279 0.0296
02:01-03:00, Tue., 10 Feb. 0.0315 0.0275 0.0293
01:01-02:00, Tue., 10 Feb. 0.0315 0.0269 0.0290
00:01-01:00, Tue., 10 Feb. 0.0308 0.0266 0.0291
23:01-24:00, Mon., 09 Feb. 0.0307 0.0256 0.0282
22:01-23:00, Mon., 09 Feb. 0.0310 0.0252 0.0279
21:01-22:00, Mon., 09 Feb. 0.0301 0.0263 0.0277
20:01-21:00, Mon., 09 Feb. 0.0300 0.0249 0.0272
19:01-20:00, Mon., 09 Feb. 0.0297 0.0249 0.0273
18:01-19:00, Mon., 09 Feb. 0.0291 0.0252 0.0269
17:01-18:00, Mon., 09 Feb. 0.0290 0.0254 0.0270
16:01-17:00, Mon., 09 Feb. 0.0296 0.0254 0.0271
15:01-16:00, Mon., 09 Feb. 0.0297 0.0253 0.0274
14:01-15:00, Mon., 09 Feb. 0.0301 0.0251 0.0274
13:01-14:00, Mon., 09 Feb. 0.0289 0.0253 0.0273
12:01-13:00, Mon., 09 Feb. 0.0287 0.0250 0.0271
11:01-12:00, Mon., 09 Feb. 0.0293 0.0246 0.0269
10:01-11:00, Mon., 09 Feb. 0.0284 0.0252 0.0270
09:01-10:00, Mon., 09 Feb. 0.0289 0.0256 0.0270
08:01-09:00, Mon., 09 Feb. 0.0292 0.0255 0.0272
07:01-08:00, Mon., 09 Feb. 0.0292 0.0249 0.0272
06:01-07:00, Mon., 09 Feb. 0.0294 0.0253 0.0271
05:01-06:00, Mon., 09 Feb. 0.0291 0.0249 0.0271
04:01-05:00, Mon., 09 Feb. 0.0289 0.0246 0.0271
03:01-04:00, Mon., 09 Feb. 0.0298 0.0249 0.0271
02:01-03:00, Mon., 09 Feb. 0.0294 0.0255 0.0271
01:01-02:00, Mon., 09 Feb. 0.0298 0.0245 0.0272
00:01-01:00, Mon., 09 Feb. 0.0297 0.0257 0.0273
23:01-24:00, Sun., 08 Feb. 0.0293 0.0256 0.0273
22:01-23:00, Sun., 08 Feb. 0.0299 0.0252 0.0274
21:01-22:00, Sun., 08 Feb. 0.0301 0.0253 0.0277
20:01-21:00, Sun., 08 Feb. 0.0293 0.0255 0.0273
19:01-20:00, Sun., 08 Feb. 0.0297 0.0257 0.0274
18:01-19:00, Sun., 08 Feb. 0.0290 0.0256 0.0272
17:01-18:00, Sun., 08 Feb. 0.0286 0.0258 0.0271
16:01-17:00, Sun., 08 Feb. 0.0288 0.0253 0.0273
15:01-16:00, Sun., 08 Feb. 0.0291 0.0250 0.0271
14:01-15:00, Sun., 08 Feb. 0.0300 0.0251 0.0273
13:01-14:00, Sun., 08 Feb. 0.0298 0.0255 0.0280
12:01-13:00, Sun., 08 Feb. 0.0341 0.0273 0.0306
11:01-12:00, Sun., 08 Feb. 0.0375 0.0314 0.0339
10:01-11:00, Sun., 08 Feb. 0.0406 0.0352 0.0377
09:01-10:00, Sun., 08 Feb. 0.0394 0.0304 0.0339
08:01-09:00, Sun., 08 Feb. 0.0332 0.0282 0.0309
07:01-08:00, Sun., 08 Feb. 0.0318 0.0263 0.0293
06:01-07:00, Sun., 08 Feb. 0.0399 0.0298 0.0346
05:01-06:00, Sun., 08 Feb. 0.0476 0.0391 0.0437
04:01-05:00, Sun., 08 Feb. 0.0443 0.0349 0.0385
03:01-04:00, Sun., 08 Feb. 0.0392 0.0342 0.0369
02:01-03:00, Sun., 08 Feb. 0.0417 0.0349 0.0393
01:01-02:00, Sun., 08 Feb. 0.0415 0.0301 0.0370
00:01-01:00, Sun., 08 Feb. 0.0325 0.0283 0.0305
23:01-24:00, Sat., 07 Feb. 0.0403 0.0290 0.0344
22:01-23:00, Sat., 07 Feb. 0.0396 0.0336 0.0367
21:01-22:00, Sat., 07 Feb. 0.0375 0.0315 0.0345
20:01-21:00, Sat., 07 Feb. 0.0339 0.0295 0.0316
19:01-20:00, Sat., 07 Feb. 0.0331 0.0265 0.0303
18:01-19:00, Sat., 07 Feb. 0.0307 0.0264 0.0283
17:01-18:00, Sat., 07 Feb. 0.0300 0.0270 0.0286
16:01-17:00, Sat., 07 Feb. 0.0321 0.0270 0.0294
15:01-16:00, Sat., 07 Feb. 0.0343 0.0288 0.0315
14:01-15:00, Sat., 07 Feb. 0.0429 0.0321 0.0372
13:01-14:00, Sat., 07 Feb. 0.0437 0.0347 0.0393
12:01-13:00, Sat., 07 Feb. 0.0384 0.0306 0.0338
11:01-12:00, Sat., 07 Feb. 0.0346 0.0297 0.0322
10:01-11:00, Sat., 07 Feb. 0.0322 0.0284 0.0307
09:01-10:00, Sat., 07 Feb. 0.0322 0.0276 0.0298
08:01-09:00, Sat., 07 Feb. 0.0317 0.0270 0.0291
07:01-08:00, Sat., 07 Feb. 0.0310 0.0274 0.0291
06:01-07:00, Sat., 07 Feb. 0.0308 0.0266 0.0291
05:01-06:00, Sat., 07 Feb. 0.0313 0.0267 0.0290
04:01-05:00, Sat., 07 Feb. 0.0330 0.0264 0.0292
03:01-04:00, Sat., 07 Feb. 0.0311 0.0260 0.0289
02:01-03:00, Sat., 07 Feb. 0.0317 0.0263 0.0288
01:01-02:00, Sat., 07 Feb. 0.0308 0.0273 0.0291
00:01-01:00, Sat., 07 Feb. 0.0303 0.0263 0.0288
23:01-24:00, Fri., 06 Feb. 0.0311 0.0270 0.0288
22:01-23:00, Fri., 06 Feb. 0.0315 0.0271 0.0290
21:01-22:00, Fri., 06 Feb. 0.0324 0.0264 0.0291
20:01-21:00, Fri., 06 Feb. 0.0311 0.0273 0.0291
19:01-20:00, Fri., 06 Feb. 0.0318 0.0271 0.0290
18:01-19:00, Fri., 06 Feb. 0.0310 0.0267 0.0289
17:01-18:00, Fri., 06 Feb. 0.0304 0.0268 0.0287
16:01-17:00, Fri., 06 Feb. 0.0315 0.0270 0.0291
15:01-16:00, Fri., 06 Feb. 0.0313 0.0271 0.0291
14:01-15:00, Fri., 06 Feb. 0.0311 0.0273 0.0291
13:01-14:00, Fri., 06 Feb. 0.0315 0.0269 0.0292
12:01-13:00, Fri., 06 Feb. 0.0318 0.0276 0.0294
11:01-12:00, Fri., 06 Feb. 0.0316 0.0276 0.0295
10:01-11:00, Fri., 06 Feb. 0.0326 0.0278 0.0306
09:01-10:00, Fri., 06 Feb. 0.0336 0.0290 0.0313
08:01-09:00, Fri., 06 Feb. 0.0339 0.0297 0.0318
07:01-08:00, Fri., 06 Feb. 0.0344 0.0286 0.0315
06:01-07:00, Fri., 06 Feb. 0.0329 0.0296 0.0314
05:01-06:00, Fri., 06 Feb. 0.0332 0.0295 0.0314
04:01-05:00, Fri., 06 Feb. 0.0336 0.0290 0.0312
03:01-04:00, Fri., 06 Feb. 0.0332 0.0292 0.0310
02:01-03:00, Fri., 06 Feb. 0.0332 0.0287 0.0306
01:01-02:00, Fri., 06 Feb. 0.0330 0.0282 0.0305
00:01-01:00, Fri., 06 Feb. 0.0325 0.0287 0.0304
23:01-24:00, Thu., 05 Feb. 0.0334 0.0279 0.0300
22:01-23:00, Thu., 05 Feb. 0.0323 0.0269 0.0293
21:01-22:00, Thu., 05 Feb. 0.0309 0.0273 0.0289
20:01-21:00, Thu., 05 Feb. 0.0311 0.0268 0.0289
19:01-20:00, Thu., 05 Feb. 0.0304 0.0262 0.0287
18:01-19:00, Thu., 05 Feb. 0.0308 0.0260 0.0286
17:01-18:00, Thu., 05 Feb. 0.0310 0.0267 0.0285
16:01-17:00, Thu., 05 Feb. 0.0310 0.0275 0.0291
15:01-16:00, Thu., 05 Feb. 0.0313 0.0270 0.0293
14:01-15:00, Thu., 05 Feb. 0.0320 0.0268 0.0295
13:01-14:00, Thu., 05 Feb. 0.0317 0.0274 0.0293
12:01-13:00, Thu., 05 Feb. 0.0322 0.0269 0.0292
11:01-12:00, Thu., 05 Feb. 0.0325 0.0281 0.0300
10:01-11:00, Thu., 05 Feb. 0.0336 0.0278 0.0306
09:01-10:00, Thu., 05 Feb. 0.0332 0.0291 0.0309
08:01-09:00, Thu., 05 Feb. 0.0345 0.0300 0.0318
07:01-08:00, Thu., 05 Feb. 0.0355 0.0302 0.0324
06:01-07:00, Thu., 05 Feb. 0.0351 0.0304 0.0325
05:01-06:00, Thu., 05 Feb. 0.0343 0.0294 0.0319
04:01-05:00, Thu., 05 Feb. 0.0343 0.0297 0.0317
03:01-04:00, Thu., 05 Feb. 0.0328 0.0292 0.0310
02:01-03:00, Thu., 05 Feb. 0.0333 0.0295 0.0310
01:01-02:00, Thu., 05 Feb. 0.0335 0.0284 0.0305
00:01-01:00, Thu., 05 Feb. 0.0325 0.0282 0.0304
23:01-24:00, Wed., 04 Feb. 0.0316 0.0274 0.0299
22:01-23:00, Wed., 04 Feb. 0.0317 0.0283 0.0299
21:01-22:00, Wed., 04 Feb. 0.0324 0.0273 0.0296
20:01-21:00, Wed., 04 Feb. 0.0329 0.0271 0.0289
19:01-20:00, Wed., 04 Feb. 0.0303 0.0263 0.0287
18:01-19:00, Wed., 04 Feb. 0.0307 0.0259 0.0283
17:01-18:00, Wed., 04 Feb. 0.0298 0.0269 0.0283
16:01-17:00, Wed., 04 Feb. 0.0308 0.0268 0.0288
15:01-16:00, Wed., 04 Feb. 0.0314 0.0270 0.0289
14:01-15:00, Wed., 04 Feb. 0.0310 0.0268 0.0290
13:01-14:00, Wed., 04 Feb. 0.0316 0.0266 0.0289
12:01-13:00, Wed., 04 Feb. 0.0311 0.0270 0.0290
11:01-12:00, Wed., 04 Feb. 0.0310 0.0264 0.0290
10:01-11:00, Wed., 04 Feb. 0.0315 0.0267 0.0291
09:01-10:00, Wed., 04 Feb. 0.0321 0.0270 0.0298
08:01-09:00, Wed., 04 Feb. 0.0328 0.0287 0.0305
07:01-08:00, Wed., 04 Feb. 0.0329 0.0286 0.0306
06:01-07:00, Wed., 04 Feb. 0.0325 0.0282 0.0302
05:01-06:00, Wed., 04 Feb. 0.0315 0.0280 0.0298
04:01-05:00, Wed., 04 Feb. 0.0314 0.0273 0.0297
03:01-04:00, Wed., 04 Feb. 0.0319 0.0276 0.0299
02:01-03:00, Wed., 04 Feb. 0.0322 0.0270 0.0295
01:01-02:00, Wed., 04 Feb. 0.0322 0.0273 0.0296
00:01-01:00, Wed., 04 Feb. 0.0317 0.0278 0.0297
23:01-24:00, Tue., 03 Feb. 0.0312 0.0264 0.0289
22:01-23:00, Tue., 03 Feb. 0.0313 0.0262 0.0285
21:01-22:00, Tue., 03 Feb. 0.0305 0.0269 0.0285
20:01-21:00, Tue., 03 Feb. 0.0299 0.0262 0.0283