Temperature trend over Italy from 1961 to 2004

Summary In order to evaluate the temperature trend over Italy, minimum and maximum daily temperatures reported by SYREP messages from 49 meteorological stations of the national air force weather service from 1961 to 2004 have been collected, controlled and used to calculate the annual series of mean temperature anomalies over Italy, with respect to the 30-years climatological period 1961–1990. Monthly temperature series were homogenized in order to eliminate the effects of non-climatic factors. Then, three trend models (linear, piecewise and sloped steps) were applied and the trends of mean temperature and average minimum and maximum temperature, together with their confidence intervals, were estimated. The results indicate a negative trend for the period 1961–1981, a more pronounced positive trend from 1981 to 2004, and an increase of the average daily temperature range for the whole period. Authors’ address: Andrea Toreti, Franco Desiato, Agenzia per la Protezione dell’Ambiente e per i Servizi Tecnici (APAT), Dipartimento Stato dell’ambiente e metrologia ambientale, Servizio sviluppo sostenibilie e cambiamenti climatici, Settore clima e meteorologia, Via Vitaliano Brancati 48, 00144 Rome, Italy.