Abstract
Relationship between solar activity and precipitation was studied by means of key day analysis. Daily amounts of precipitation are averaged at several stations in the Far East during the period of intense solar flare and strong and weak geomagnetic disturbance. Distinct increase of precipitation is found on days with intense solar flare. This suggests that soft X ray or very fast particle flow (probably cosmic rays emmitted from solar flare) stimulates the precipitation. Increases of precipitation are also found at some stations on days with strong geomagnetic disturbance or 6 days later. This may be due to secondary circulations which are stimulated by the initial responses.
