Data Format (until March 2024)
| 1. | Observation times are Japan Standard Time (UTC +9). |
| 2. | Solar radiation data are written in the scale of the World Radiometric Reference (WRR). Infrared radiation data are based on the universal standard to ensure traceability to the World Infrared Standard Group of Pyrgeometers (WISG). |
| 3. | Fractional data are rounded down to the nearest whole number. |
| 4. | Data are not shown for months where fewer than 20 days of information are available. |
| 5. | “)” to the right of numbers and “*)” below numbers indicate statistics with missing data. |
| 6. | Hourly data are integrated values covering the period from 01 min of one hour to 00 min of the next (e.g., hourly data for 09 are integrated values covering the period from 08 h 01 m to 09 h 00 m). |
| 7. | N indicates the number of observation dates without missing days. |
| 8. | Monthly averages for periods with missing data are calculated by dividing the monthly total value by the number of days in the month for which observation data are available. |