Chronological series (1949 to 1992) of air temperature, precipitation, atmospheric pressure and wind in different parts of the French coast show evidence of important year-to-year changes, trends and cycles: seven-eight years for temperature, and around three years for precipitation and atmospheric pressure. On the scale of France, it appears that spatial heterogeneity of meteorological factors is smaller than temporal heterogeneity. New methods, such as the cumulative sums method or the envelopes of a variable reveal the interest for ecologists of essaying different numerical approaches. A comparison between climatic series and biological series of a benthic and a pelagic species is described for this purpose.