Stockholm Historical Weather Observations — Daily mean air temperatures since 1756 (graphics)

Anders Moberg

Weather observations of several meteorological variables have been made continuously at the old astronomical observatory in Stockholm since 1756. As a part of a collection of data for selected variables, the dataset provided here contains figures that illustrate daily mean air temperatures in each separate year within the period 1756–2018. The underlying temperature data have been adjusted after 1870 to exclude the local urban warming trend in the city and also has an additional adjustment applied to data for May–August in the period before 1859, to correct for a supposed warm bias of the observed temperatures due to likely poor protection of thermometers against radiation.

Data description

The dataset contains png files with visualizations of daily mean temperature data in each of the 263 years between 1756 and 2018. Two variants are provided; one set of figures with English labels and one with Swedish labels.

Each figure shows the daily average temperature for each day for a given year, in red or blue, depending on whether the temperature is above or below the average calculated for the corresponding calendar date during the 250-year period 1756–2005 (plotted in thick black). Also shown are the lowest and highest observed daily mean temperature (thin black) and the 5th and 95th percentiles (green) for each calendar date in all years between 1756 and 2005.

Comments

The temperature data used to create these figure files are those found in column 6 in the associated dataset with daily mean temperatures.

The observation site is included in the national station network managed by the Swedish Meteorological and Hydrological Institute (SMHI), with station number 98210 (manual station) and 98230 (automatic station), but data used for the current set of figures can differ from those in the SMHI database.