This is the peer reviewed version of the following article: Mazon, J., Pino, D. Meteodiversity: a new concept for quantifying meteorological diversity. "Weather", 10 Maig 2017, vol. 72, núm. 5, p. 143-145., which has been published in final form at http://onlinelibrary.wiley.com/wol1/doi/10.1002/wea.2945/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Inspired by the concept of biodiversity used by biologists and ecologists, the concept of meteodiversity is proposed as a method of characterising the variety of meteorological phenomena in a defined area within a specified period. Similarly to the term biodiversity, meteodiversity takes into account the proportion of individual meteorological phenomena belonging to the main weather that occur in a defined area. The benefits and importance of using this concept are discussed. For quantification purposes, we propose a meteodiversity index, which, in addition to events and phenomena, should include a large number of atmospheric variables obtained from instrumental and observational records. This index itemises not only events ans phenomena, but also a large number of atmospheric variables obtained from instrumental and observational records. We use climatic data obtained from the Met Office and European Climate Assessment and Dataset project to evaluate the meteodiversity index, first on a monthly scale for the period 1981–2014 at Llanfairpwllgwyngyll (UK), and then on an annual scale for 1962–2014 at Barcelona (Spain) and Helsinki (Finland). The weather diversity and the trends over these cities have been analyzed. Peer Reviewed