Statistical analysis of temperature extremes in long-time series from Uppsala

Temperature records in Uppsala, Sweden, during the period 1840–2001, are analysed. More precisely, yearly maxima and minima are studied in order to investigate possible trends. Extreme-value distributions are fitted, and a nonstationary model is introduced by allowing for a time-dependent location parameter. Comparisons are made with an estimated trend for mean temperature. In addition, a Mann–Kendall test is performed in order to investigate a present trend. The results obtained from the statistical models agree with those found earlier by descriptive statistics, in particular an increasing trend for the coldest days of the year.