| Year | Month | Event |
|---|---|---|
| 1920 | 8 | Establishment of meteorological observatory for professional observation of upper air |
| 11 | Start of surface meteorological observation | |
| 1921 | 4 | Start of upper-wind observation using a small balloon and a balloon theodolite |
| 1922 | 12 | Start of lower aerological observation (pressure, temperature and humidity) using a kite and a kytoon |
| 1924 | 12 | Discovery of jet stream |
| 1925 | 8 | Start of observation (pressure, temperature and humidity) using a sounding balloon equipped with an automatic weather meter |
| 1944 | 9 | Start of radiosonde observation (pressure, temperature and humidity) |
| 1948 | 11 | Start of rawin observation (wind and pressure) |
| 1955 | 7 | Start of ozone observation using a Dobson spectrophotometer |
| 1957 | 4 | Start of rawinsonde observation (00 and 12 UTC; pressure, temperature, humidity and wind) |
| 7 | Start of solar radiation and infrared radiation observation | |
| 1968 | 3 | Start of ozone concentration observation using an ozonesonde in the troposphere from the lower stratosphere |
| 1975 | 3 | Relocation to the current premises |
| 1990 | 1 | Start of observation of individual wavelengths in ultraviolet-range solar radiation using a Brewer spectrophotometer |
| 1993 | 2 - 3 | Hosting of WMO radiosonde international comparison at the Aerological Observatory in Japan (with representation from the United States, the United Kingdom and Finland) |
| 1994 - 1996 | - | Conduct of experiments on steady wind observation using wind profiler lidar (Aerological Observatory, Observation Department, Forecast Department, Meteorological Research Institute) |
| 1996 | 2 | Registration with the Baseline Surface Radiation Network (BSRN) |
| 2 - 3 8 - 9 | Hosting of Asia-Pacific Ocean region ozone workshop/ozone international comparison at the Aerological Observatory in Japan (with representation from India, South Korea, Thailand, the Philippines, China, Pakistan and Malaysia) | |
| 1999 | 7 | Start of high-altitude rawinsonde observation (5 hPa, 35 km) |
| 2002 | 1 | Start of highly accurate observation of individual-wavelength ultraviolet range solar radiation |
| 2003 | 3 | Hosting of Dobson spectrophotometer Pacific Asia district comparison at the Aerological Observatory in Japan (with representation from China) |
| 2004 | 3 | Termination of rawin observation |
| 2005 | 5 | Start of UV information provision by the Japan Meteorological Agency |
| 2006 | 3 | Hosting of Dobson spectrophotometer Pacific Asia district comparison at the Aerological Observatory in Japan (with representation from India, Iran, Pakistan, Thailand and the Philippines) |
| 2008 | 1 | Establishment of global standards and compliance in infrared radiation observation |
| 2009 | 9 | Participation in GRUAN (the GCOS Reference Upper Air Network) (15th location worldwide) |
| 11 | Start of precipitable water vapor observation using a GPS receiver | |
| 12 | Start of wind observation using wind profiler lidar | |
| Start of radiosonde and ozonesonde observation using a GPS sonde | ||
| 2011 | 9 | Hosting of Dobson spectrophotometer Pacific Asia district comparison at the Aerological Observatory in Japan (with representation from China) |
| 2012 | 3 | Hosting of the 4th GRUAN implementation coordination meeting at the Japan Meteorological Agency and site visits to the Aerological Observatory |
| 4 | Integrated operation of surface meteorological observation and aerological observation | |
| 2013 | 3 | Termination of kytoon observation |
| 2015 | 3 | Termination of high-altitude observation |
| 2018 | 4 | Certification acquisition as GRUAN radiosounding site |
| 2020 | 8 | Publication of A Century of Aerological Observatory Operation |