Measurements of the concentration of freezing nuclei in the atmosphere have been made in widely separated parts of the globe during January in one or more of the three successive years 1954, 1955, and 1956. The results of all three sets of observations are summarized and it is shown that high freezing nucleus counts tend to occur on dates which are identical or nearly identical with those on which unusually heavy falls of rain have previously been shown to occur. The results are discussed in relation to the possible connexion between meteoritic dust and world rainfall.