We analyze century‐long daily temperature and precipitation records for stations in Europe west of 60°E. A set of climatic indices derived from the daily series, mainly focusing on extremes, is defined. Linear trends in these indices are assessed over the period 1901–2000. Average trends, for 75 stations mostly representing Europe west of 20°E, show a warming for all temperature indices. Winter has, on average, warmed more (∼1.0°C/100 yr) than summer (∼0.8°C), both for daily maximum (TX) and minimum (TN) temperatures. Overall, the warming of TX in winter was stronger in the warm tail than in the cold tail (1.6 and 1.5°C for 98th and 95th, but ∼1.0°C for 2nd, 5th and 10th percentiles). There are, however, large regional differences in temperature trend patterns. For summer, there is a tendency for stronger warming, both for TX and TN, in the warm than in the cold tail only in parts of central Europe. Winter precipitation totals, averaged over 121 European stations north of 40°N, have increased significantly by ∼12% per 100 years. Trends in 90th, 95th and 98th percentiles of daily winter precipitation have been similar. No overall long‐term trend occurred in summer precipitation totals, but there is an overall weak (statistically insignificant and regionally dependent) tendency for summer precipitation to have become slightly more intense but less common. Data inhomogeneities and relative sparseness of station density in many parts of Europe preclude more robust conclusions. It is of importance that new methods are developed for homogenizing daily data.

The development of a daily historical European–North Atlantic mean sea level pressure dataset (EMSLP) for 1850–2003 on a 5° latitude by longitude grid is described. This product was produced using 86 continental and island stations distributed over the region 25°–70°N, 70°W–50°E blended with marine data from the International Comprehensive Ocean–Atmosphere Data Set (ICOADS). The EMSLP fields for 1850–80 are based purely on the land station data and ship observations. From 1881, the blended land and marine fields are combined with already available daily Northern Hemisphere fields. Complete coverage is obtained by employing reduced space optimal interpolation. Squared correlations (r 2) indicate that EMSLP generally captures 80%–90% of daily variability represented in an existing historical mean sea level pressure product and over 90% in modern 40-yr European Centre for Medium-Range Weather Forecasts Re-Analyses (ERA-40) over most of the region. A lack of sufficient observations over Greenland and the Middle East, however, has resulted in poorer reconstructions there. Error estimates, produced as part of the reconstruction technique, flag these as regions of low confidence. It is shown that the EMSLP daily fields and associated error estimates provide a unique opportunity to examine the circulation patterns associated with extreme events across the European–North Atlantic region, such as the 2003 heat wave, in the context of historical events.

We analyze temporal and spatial patterns of temperature change over Spain during the period 1850–2005, using daily maximum (T_max), minimum (T_min), and mean (T_mean) temperatures from the 22 longest and most reliable Spanish records. Over mainland Spain, a significant (at 0.01 level) warming of 0.10°C/decade is found for the annual average of T_mean. Autumn and winter contributed slightly more than spring and summer to the annual warming over the 1850–2005 period. The overall warming is also associated with higher rates of change for T_max than T_min (0.11° versus 0.08°C/decade for 1850–2005). This asymmetric diurnal warming increased in the twentieth century (0.17° versus 0.09°C/decade during 1901–2005). Nevertheless, at many (few) individual stations, the difference between T_max and T_min is not statistically significant over 1850–2005 (1901–2005). Principal Component Analysis has been carried out to identify spatial modes of Spanish long‐term temperature variability (1901–2005). Three principal spatial patterns are found, Northern Spain, Southeastern and Eastern Spain, and Southwestern Spain. All three patterns show similar significant warming trends. The overall warming has been more associated with reductions in cold extremes, as opposed to increases in warm extremes. Estimated trends in the number of moderately extreme cold days (T_max < 10th percentile) and moderately extreme cold nights (T_min < 10th percentile) show significant reductions of 0.74 and 0.54 days/decade, respectively, over 1850–2005. Moderately extreme warm days and nights (T_max and T_min > 90th percentile) increased significantly but at lower rates of 0.53 and 0.49 days/decade.

Here we present the development of a new adjusted dataset composed of the 22 longest and most reliable Spanish daily temperature records (maximum and minimum temperatures and derived daily mean temperature) covering the period 1850–2003. The paper describes the approaches followed for compiling, controlling the quality and homogenising these 22 daily Spanish records, leading to the creation of a dataset called ‘Spanish Daily Adjusted Temperature Series’ (SDATS). An assessment of the sources of data and metadata used is followed by a reliability assessment of the selected network. Data quality control (QC) procedures applied to raw daily maximum (T_max) and minimum (T_min) temperatures and their results are then considered. For the very first time, an empirical minimisation of the bias related to the impact of changing exposure of thermometers on the records has been undertaken. The application of the Standard Normal Homogeneity Test (SNHT) to check homogeneity of raw T_max and T_min data on a monthly basis is presented, together with a discussion of the causes, magnitudes and timings of the various inhomogeneities. All 22 records contained a number of inhomogeneities (2.6 on average), mainly associated with documented station relocations confirmed by the metadata available. Monthly adjustments calculated for both screen developments and from the SNHT were linearly interpolated to a daily basis following the Vincent et al. ( 2002 ) scheme. Finally, the procedures adopted for creating the regional average, the Spanish Temperature Series (STS), together with an exploratory analysis of long-term trends of each T_max and T_min records, are provided. The final analysis shows that over mainland Spain highly significant rates of temperature increases have occurred for T_max and T_min (0.12 °C/decade and 0.10 °C/decade, respectively) over 1850–2003. Copyright © 2006 Royal Meteorological Society.

[1] This study provides the first long‐term assessment of changes in precipitation associated with different rainfall categories over the Iberian Peninsula (IP). Using recently digitized data from 27 stations in Portugal and Spain, we have examined trends of precipitation indices for the complete period 1903–2003 and the two subperiods 1903–1953 and 1954–2003. These indices were evaluated seasonally according to five rainfall categories: total rainfall (≥0.2 mm), light rainfall (≥0.2 and <2.5 mm), moderate rainfall (≥2.5 and <7.5 mm), intense rainfall (≥7.5 mm), and very intense rainfall (≥15 mm). For the complete period 1903–2003, we have found that the total number of rainy days and that of light rainfall are increasing at many observatories over the IP for all seasons (except in the western zone of Portugal and the Cádiz gulf, where they are decreasing). Both subperiods show opposite behaviors in fall and spring. During the first (second) subperiod spanning 1903–1953 (1954–2003), we can find a generalized decrease (increase) in the number of rainy days in fall in all rainfall categories. In spring, an increase in the number of rainy days is found mainly for total, moderate, and intense categories for the first subperiod, and a slight decrease during the second. In winter, we have verified a decrease in the number of rainy days mainly for total, moderate, and intense rainfall categories in the second subperiod. Finally in relation to the maximum length of dry spells for both subperiods, most observatories show significant trends opposite those of the total number of rainy days. It is worth noticing that the contrasting evolution of trends found between the first and second halves of the twentieth century could only be characterized in this work following a recent comprehensive digitization of historical Iberian precipitation data from the first decades of the twentieth century.