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
11:01-12:00, Sun., 23 Feb. 0.0297 0.0256 0.0277
10:01-11:00, Sun., 23 Feb. 0.0299 0.0257 0.0274
09:01-10:00, Sun., 23 Feb. 0.0299 0.0259 0.0278
08:01-09:00, Sun., 23 Feb. 0.0301 0.0254 0.0280
07:01-08:00, Sun., 23 Feb. 0.0310 0.0259 0.0283
06:01-07:00, Sun., 23 Feb. 0.0301 0.0250 0.0281
05:01-06:00, Sun., 23 Feb. 0.0318 0.0272 0.0287
04:01-05:00, Sun., 23 Feb. 0.0313 0.0268 0.0289
03:01-04:00, Sun., 23 Feb. 0.0311 0.0273 0.0292
02:01-03:00, Sun., 23 Feb. 0.0319 0.0271 0.0292
01:01-02:00, Sun., 23 Feb. 0.0318 0.0261 0.0285
00:01-01:00, Sun., 23 Feb. 0.0296 0.0249 0.0275
23:01-24:00, Sat., 22 Feb. 0.0300 0.0262 0.0279
22:01-23:00, Sat., 22 Feb. 0.0305 0.0261 0.0276
21:01-22:00, Sat., 22 Feb. 0.0305 0.0249 0.0277
20:01-21:00, Sat., 22 Feb. 0.0302 0.0253 0.0277
19:01-20:00, Sat., 22 Feb. 0.0293 0.0260 0.0274
18:01-19:00, Sat., 22 Feb. 0.0292 0.0253 0.0273
17:01-18:00, Sat., 22 Feb. 0.0297 0.0256 0.0276
16:01-17:00, Sat., 22 Feb. 0.0298 0.0256 0.0278
15:01-16:00, Sat., 22 Feb. 0.0298 0.0258 0.0278
14:01-15:00, Sat., 22 Feb. 0.0302 0.0256 0.0277
13:01-14:00, Sat., 22 Feb. 0.0303 0.0250 0.0276
12:01-13:00, Sat., 22 Feb. 0.0310 0.0261 0.0280
11:01-12:00, Sat., 22 Feb. 0.0312 0.0256 0.0279
10:01-11:00, Sat., 22 Feb. 0.0296 0.0255 0.0277
09:01-10:00, Sat., 22 Feb. 0.0302 0.0256 0.0277
08:01-09:00, Sat., 22 Feb. 0.0299 0.0263 0.0278
07:01-08:00, Sat., 22 Feb. 0.0304 0.0262 0.0281
06:01-07:00, Sat., 22 Feb. 0.0307 0.0255 0.0279
05:01-06:00, Sat., 22 Feb. 0.0301 0.0253 0.0280
04:01-05:00, Sat., 22 Feb. 0.0308 0.0254 0.0278
03:01-04:00, Sat., 22 Feb. 0.0297 0.0250 0.0275
02:01-03:00, Sat., 22 Feb. 0.0309 0.0245 0.0276
01:01-02:00, Sat., 22 Feb. 0.0294 0.0252 0.0277
00:01-01:00, Sat., 22 Feb. 0.0301 0.0260 0.0277
23:01-24:00, Fri., 21 Feb. 0.0294 0.0260 0.0277
22:01-23:00, Fri., 21 Feb. 0.0293 0.0250 0.0272
21:01-22:00, Fri., 21 Feb. 0.0298 0.0253 0.0272
20:01-21:00, Fri., 21 Feb. 0.0291 0.0249 0.0272
19:01-20:00, Fri., 21 Feb. 0.0293 0.0250 0.0272
18:01-19:00, Fri., 21 Feb. 0.0301 0.0253 0.0273
17:01-18:00, Fri., 21 Feb. 0.0294 0.0249 0.0274
16:01-17:00, Fri., 21 Feb. 0.0298 0.0256 0.0274
15:01-16:00, Fri., 21 Feb. 0.0290 0.0252 0.0274
14:01-15:00, Fri., 21 Feb. 0.0299 0.0262 0.0279
13:01-14:00, Fri., 21 Feb. 0.0298 0.0259 0.0279
12:01-13:00, Fri., 21 Feb. 0.0297 0.0249 0.0279
11:01-12:00, Fri., 21 Feb. 0.0294 0.0262 0.0278
10:01-11:00, Fri., 21 Feb. 0.0297 0.0258 0.0277
09:01-10:00, Fri., 21 Feb. 0.0298 0.0253 0.0277
08:01-09:00, Fri., 21 Feb. 0.0304 0.0254 0.0281
07:01-08:00, Fri., 21 Feb. 0.0297 0.0259 0.0280
06:01-07:00, Fri., 21 Feb. 0.0298 0.0259 0.0279
05:01-06:00, Fri., 21 Feb. 0.0298 0.0260 0.0280
04:01-05:00, Fri., 21 Feb. 0.0298 0.0256 0.0278
03:01-04:00, Fri., 21 Feb. 0.0294 0.0258 0.0277
02:01-03:00, Fri., 21 Feb. 0.0304 0.0259 0.0278
01:01-02:00, Fri., 21 Feb. 0.0298 0.0263 0.0279
00:01-01:00, Fri., 21 Feb. 0.0303 0.0251 0.0276
23:01-24:00, Thu., 20 Feb. 0.0295 0.0256 0.0274
22:01-23:00, Thu., 20 Feb. 0.0302 0.0254 0.0276
21:01-22:00, Thu., 20 Feb. 0.0301 0.0249 0.0272
20:01-21:00, Thu., 20 Feb. 0.0290 0.0248 0.0273
19:01-20:00, Thu., 20 Feb. 0.0297 0.0247 0.0274
18:01-19:00, Thu., 20 Feb. 0.0292 0.0249 0.0271
17:01-18:00, Thu., 20 Feb. 0.0288 0.0249 0.0270
16:01-17:00, Thu., 20 Feb. 0.0298 0.0259 0.0271
15:01-16:00, Thu., 20 Feb. 0.0291 0.0249 0.0270
14:01-15:00, Thu., 20 Feb. 0.0301 0.0254 0.0275
13:01-14:00, Thu., 20 Feb. 0.0294 0.0256 0.0274
12:01-13:00, Thu., 20 Feb. 0.0300 0.0259 0.0276
11:01-12:00, Thu., 20 Feb. 0.0294 0.0253 0.0275
10:01-11:00, Thu., 20 Feb. 0.0299 0.0256 0.0276
09:01-10:00, Thu., 20 Feb. 0.0293 0.0255 0.0274
08:01-09:00, Thu., 20 Feb. 0.0314 0.0259 0.0281
07:01-08:00, Thu., 20 Feb. 0.0300 0.0262 0.0282
06:01-07:00, Thu., 20 Feb. 0.0301 0.0258 0.0279
05:01-06:00, Thu., 20 Feb. 0.0299 0.0262 0.0280
04:01-05:00, Thu., 20 Feb. 0.0322 0.0263 0.0282
03:01-04:00, Thu., 20 Feb. 0.0304 0.0249 0.0281
02:01-03:00, Thu., 20 Feb. 0.0304 0.0259 0.0281
01:01-02:00, Thu., 20 Feb. 0.0302 0.0254 0.0278
00:01-01:00, Thu., 20 Feb. 0.0297 0.0256 0.0278
23:01-24:00, Wed., 19 Feb. 0.0299 0.0261 0.0278
22:01-23:00, Wed., 19 Feb. 0.0301 0.0256 0.0280
21:01-22:00, Wed., 19 Feb. 0.0297 0.0256 0.0276
20:01-21:00, Wed., 19 Feb. 0.0290 0.0259 0.0278
19:01-20:00, Wed., 19 Feb. 0.0302 0.0252 0.0276
18:01-19:00, Wed., 19 Feb. 0.0305 0.0261 0.0275
17:01-18:00, Wed., 19 Feb. 0.0304 0.0255 0.0276
16:01-17:00, Wed., 19 Feb. 0.0295 0.0249 0.0276
15:01-16:00, Wed., 19 Feb. 0.0296 0.0249 0.0277
14:01-15:00, Wed., 19 Feb. 0.0297 0.0256 0.0279
13:01-14:00, Wed., 19 Feb. 0.0296 0.0256 0.0276
12:01-13:00, Wed., 19 Feb. 0.0297 0.0257 0.0278
11:01-12:00, Wed., 19 Feb. 0.0297 0.0255 0.0278
10:01-11:00, Wed., 19 Feb. 0.0304 0.0259 0.0278
09:01-10:00, Wed., 19 Feb. 0.0303 0.0256 0.0280
08:01-09:00, Wed., 19 Feb. 0.0299 0.0261 0.0277
07:01-08:00, Wed., 19 Feb. 0.0305 0.0253 0.0278
06:01-07:00, Wed., 19 Feb. 0.0310 0.0265 0.0282
05:01-06:00, Wed., 19 Feb. 0.0315 0.0264 0.0284
04:01-05:00, Wed., 19 Feb. 0.0309 0.0266 0.0284
03:01-04:00, Wed., 19 Feb. 0.0303 0.0265 0.0285
02:01-03:00, Wed., 19 Feb. 0.0308 0.0253 0.0285
01:01-02:00, Wed., 19 Feb. 0.0322 0.0260 0.0283
00:01-01:00, Wed., 19 Feb. 0.0299 0.0269 0.0286
23:01-24:00, Tue., 18 Feb. 0.0299 0.0265 0.0282
22:01-23:00, Tue., 18 Feb. 0.0301 0.0259 0.0280
21:01-22:00, Tue., 18 Feb. 0.0297 0.0262 0.0282
20:01-21:00, Tue., 18 Feb. 0.0300 0.0257 0.0278
19:01-20:00, Tue., 18 Feb. 0.0300 0.0262 0.0279
18:01-19:00, Tue., 18 Feb. 0.0300 0.0256 0.0276
17:01-18:00, Tue., 18 Feb. 0.0298 0.0249 0.0280
16:01-17:00, Tue., 18 Feb. 0.0297 0.0261 0.0280
15:01-16:00, Tue., 18 Feb. 0.0301 0.0259 0.0278
14:01-15:00, Tue., 18 Feb. 0.0303 0.0259 0.0280
13:01-14:00, Tue., 18 Feb. 0.0298 0.0256 0.0281
12:01-13:00, Tue., 18 Feb. 0.0296 0.0257 0.0278
11:01-12:00, Tue., 18 Feb. 0.0307 0.0259 0.0284
10:01-11:00, Tue., 18 Feb. 0.0303 0.0252 0.0279
09:01-10:00, Tue., 18 Feb. 0.0307 0.0250 0.0280
08:01-09:00, Tue., 18 Feb. 0.0311 0.0261 0.0282
07:01-08:00, Tue., 18 Feb. 0.0308 0.0262 0.0285
06:01-07:00, Tue., 18 Feb. 0.0309 0.0270 0.0286
05:01-06:00, Tue., 18 Feb. 0.0310 0.0266 0.0287
04:01-05:00, Tue., 18 Feb. 0.0311 0.0270 0.0288
03:01-04:00, Tue., 18 Feb. 0.0310 0.0264 0.0287
02:01-03:00, Tue., 18 Feb. 0.0306 0.0266 0.0289
01:01-02:00, Tue., 18 Feb. 0.0317 0.0263 0.0291
00:01-01:00, Tue., 18 Feb. 0.0311 0.0273 0.0291
23:01-24:00, Mon., 17 Feb. 0.0304 0.0258 0.0287
22:01-23:00, Mon., 17 Feb. 0.0304 0.0261 0.0284
21:01-22:00, Mon., 17 Feb. 0.0305 0.0263 0.0282
20:01-21:00, Mon., 17 Feb. 0.0307 0.0262 0.0283
19:01-20:00, Mon., 17 Feb. 0.0301 0.0263 0.0282
18:01-19:00, Mon., 17 Feb. 0.0310 0.0263 0.0285
17:01-18:00, Mon., 17 Feb. 0.0301 0.0263 0.0283
16:01-17:00, Mon., 17 Feb. 0.0301 0.0262 0.0283
15:01-16:00, Mon., 17 Feb. 0.0304 0.0253 0.0280
14:01-15:00, Mon., 17 Feb. 0.0301 0.0259 0.0278
13:01-14:00, Mon., 17 Feb. 0.0304 0.0259 0.0281
12:01-13:00, Mon., 17 Feb. 0.0302 0.0263 0.0283
11:01-12:00, Mon., 17 Feb. 0.0307 0.0266 0.0283
10:01-11:00, Mon., 17 Feb. 0.0308 0.0266 0.0282
09:01-10:00, Mon., 17 Feb. 0.0310 0.0261 0.0285
08:01-09:00, Mon., 17 Feb. 0.0334 0.0274 0.0299
07:01-08:00, Mon., 17 Feb. 0.0325 0.0274 0.0299
06:01-07:00, Mon., 17 Feb. 0.0325 0.0276 0.0296
05:01-06:00, Mon., 17 Feb. 0.0312 0.0271 0.0290
04:01-05:00, Mon., 17 Feb. 0.0306 0.0262 0.0286
03:01-04:00, Mon., 17 Feb. 0.0307 0.0263 0.0284
02:01-03:00, Mon., 17 Feb. 0.0298 0.0258 0.0280
01:01-02:00, Mon., 17 Feb. 0.0294 0.0254 0.0277
00:01-01:00, Mon., 17 Feb. 0.0301 0.0259 0.0280
23:01-24:00, Sun., 16 Feb. 0.0298 0.0259 0.0280
22:01-23:00, Sun., 16 Feb. 0.0295 0.0257 0.0278
21:01-22:00, Sun., 16 Feb. 0.0287 0.0249 0.0272
20:01-21:00, Sun., 16 Feb. 0.0294 0.0256 0.0274
19:01-20:00, Sun., 16 Feb. 0.0288 0.0257 0.0275
18:01-19:00, Sun., 16 Feb. 0.0296 0.0252 0.0277
17:01-18:00, Sun., 16 Feb. 0.0297 0.0254 0.0273
16:01-17:00, Sun., 16 Feb. 0.0301 0.0262 0.0278
15:01-16:00, Sun., 16 Feb. 0.0305 0.0256 0.0279
14:01-15:00, Sun., 16 Feb. 0.0297 0.0264 0.0279
13:01-14:00, Sun., 16 Feb. 0.0307 0.0256 0.0279
12:01-13:00, Sun., 16 Feb. 0.0308 0.0263 0.0283
11:01-12:00, Sun., 16 Feb. 0.0306 0.0258 0.0281
10:01-11:00, Sun., 16 Feb. 0.0299 0.0260 0.0280
09:01-10:00, Sun., 16 Feb. 0.0304 0.0262 0.0288
08:01-09:00, Sun., 16 Feb. 0.0313 0.0266 0.0292
07:01-08:00, Sun., 16 Feb. 0.0308 0.0270 0.0290
06:01-07:00, Sun., 16 Feb. 0.0308 0.0261 0.0284
05:01-06:00, Sun., 16 Feb. 0.0297 0.0262 0.0280
04:01-05:00, Sun., 16 Feb. 0.0300 0.0257 0.0279
03:01-04:00, Sun., 16 Feb. 0.0298 0.0257 0.0278
02:01-03:00, Sun., 16 Feb. 0.0304 0.0263 0.0280
01:01-02:00, Sun., 16 Feb. 0.0299 0.0260 0.0277
00:01-01:00, Sun., 16 Feb. 0.0294 0.0254 0.0276
23:01-24:00, Sat., 15 Feb. 0.0287 0.0255 0.0272
22:01-23:00, Sat., 15 Feb. 0.0291 0.0248 0.0272
21:01-22:00, Sat., 15 Feb. 0.0293 0.0257 0.0271
20:01-21:00, Sat., 15 Feb. 0.0291 0.0255 0.0270
19:01-20:00, Sat., 15 Feb. 0.0287 0.0247 0.0269
18:01-19:00, Sat., 15 Feb. 0.0287 0.0250 0.0270
17:01-18:00, Sat., 15 Feb. 0.0288 0.0241 0.0270
16:01-17:00, Sat., 15 Feb. 0.0298 0.0255 0.0272
15:01-16:00, Sat., 15 Feb. 0.0297 0.0256 0.0275
14:01-15:00, Sat., 15 Feb. 0.0295 0.0252 0.0274
13:01-14:00, Sat., 15 Feb. 0.0301 0.0252 0.0275
12:01-13:00, Sat., 15 Feb. 0.0300 0.0259 0.0278
11:01-12:00, Sat., 15 Feb. 0.0294 0.0261 0.0276
10:01-11:00, Sat., 15 Feb. 0.0298 0.0256 0.0275
09:01-10:00, Sat., 15 Feb. 0.0308 0.0262 0.0279
08:01-09:00, Sat., 15 Feb. 0.0322 0.0268 0.0295
07:01-08:00, Sat., 15 Feb. 0.0313 0.0272 0.0294
06:01-07:00, Sat., 15 Feb. 0.0315 0.0266 0.0287
05:01-06:00, Sat., 15 Feb. 0.0300 0.0261 0.0280
04:01-05:00, Sat., 15 Feb. 0.0295 0.0255 0.0277
03:01-04:00, Sat., 15 Feb. 0.0294 0.0253 0.0277
02:01-03:00, Sat., 15 Feb. 0.0297 0.0252 0.0275
01:01-02:00, Sat., 15 Feb. 0.0298 0.0249 0.0274
00:01-01:00, Sat., 15 Feb. 0.0302 0.0256 0.0276
23:01-24:00, Fri., 14 Feb. 0.0299 0.0249 0.0275
22:01-23:00, Fri., 14 Feb. 0.0298 0.0252 0.0274
21:01-22:00, Fri., 14 Feb. 0.0299 0.0249 0.0273
20:01-21:00, Fri., 14 Feb. 0.0289 0.0249 0.0272
19:01-20:00, Fri., 14 Feb. 0.0295 0.0249 0.0273
18:01-19:00, Fri., 14 Feb. 0.0286 0.0251 0.0271
17:01-18:00, Fri., 14 Feb. 0.0293 0.0247 0.0272
16:01-17:00, Fri., 14 Feb. 0.0294 0.0250 0.0276
15:01-16:00, Fri., 14 Feb. 0.0306 0.0252 0.0278
14:01-15:00, Fri., 14 Feb. 0.0301 0.0263 0.0278
13:01-14:00, Fri., 14 Feb. 0.0300 0.0264 0.0282
12:01-13:00, Fri., 14 Feb. 0.0301 0.0263 0.0279
11:01-12:00, Fri., 14 Feb. 0.0294 0.0263 0.0280
10:01-11:00, Fri., 14 Feb. 0.0310 0.0259 0.0285
09:01-10:00, Fri., 14 Feb. 0.0317 0.0273 0.0293
08:01-09:00, Fri., 14 Feb. 0.0318 0.0274 0.0300
07:01-08:00, Fri., 14 Feb. 0.0325 0.0279 0.0303
06:01-07:00, Fri., 14 Feb. 0.0328 0.0279 0.0302
05:01-06:00, Fri., 14 Feb. 0.0325 0.0276 0.0299
04:01-05:00, Fri., 14 Feb. 0.0322 0.0273 0.0293
03:01-04:00, Fri., 14 Feb. 0.0308 0.0249 0.0281
02:01-03:00, Fri., 14 Feb. 0.0298 0.0255 0.0280
01:01-02:00, Fri., 14 Feb. 0.0303 0.0262 0.0279
00:01-01:00, Fri., 14 Feb. 0.0300 0.0260 0.0279
23:01-24:00, Thu., 13 Feb. 0.0296 0.0258 0.0277
22:01-23:00, Thu., 13 Feb. 0.0297 0.0257 0.0278
21:01-22:00, Thu., 13 Feb. 0.0303 0.0252 0.0279
20:01-21:00, Thu., 13 Feb. 0.0294 0.0252 0.0278
19:01-20:00, Thu., 13 Feb. 0.0295 0.0263 0.0278
18:01-19:00, Thu., 13 Feb. 0.0301 0.0262 0.0277
17:01-18:00, Thu., 13 Feb. 0.0301 0.0262 0.0279
16:01-17:00, Thu., 13 Feb. 0.0303 0.0261 0.0281
15:01-16:00, Thu., 13 Feb. 0.0298 0.0259 0.0284
14:01-15:00, Thu., 13 Feb. 0.0302 0.0261 0.0285
13:01-14:00, Thu., 13 Feb. 0.0308 0.0265 0.0288
12:01-13:00, Thu., 13 Feb. 0.0310 0.0266 0.0286