Vol. 128, No. 2 * Pages 143–286 * April - June 2024

Precipitation gauges used for observations in the 19th century are reconstructed and pairs of gauges are installed at two, climatologically different, regular weather observation sites (Norrköping and Katterjåkk). Norrköping is a quite well sheltered site with a low degree of frozen precipitation, while Katterjåkk is an open site with a high degree of frozen precipitation. One of the gauges at each site is equipped with a wind shield. Parallel observations are conducted from November 2016 through May 2021. Regular observations are also conducted manually with modern gauges and with automatic gauges at the sites.
The wind shield effects (larger observed precipitation sums due to the inclusion of a wind shield) for the sheltered (Norrköping) and the open (Katterjåkk) sites are 7% and 16% for snow and 2% and 1% for rain, respectively.
The modern gauges generally collect more precipitation than the historical shielded gauges, the difference is 0–8% for rain and almost up to 50% for snow. However, these differences can, in part, be ascribed to micrometeorologal conditions at the sites.
The differences between observation methods are larger for snow and sleet than for rain. There are also larger differences in the open site than in the sheltered site.
The most closely placed modern gauge relative to the historical gauges (automatic gauge in Norrköping, manual gauge in Katterjåkk) gives the most similar precipitation sums, suggesting that micrometeorology is more important than the observation method.
The undercatch due to lacking wind shields in historical observations can probably not explain more than 20% of the increased observed precipitation in the late 19th and early 20th century.
The question of potential influence on climatological precipitation series due to the transition from historical to modern observation methods remains unconcluded.