Quality controlled and gap-filled continuous air temperature data measured inside the forest canopy at Hartheim Forest Research Site (ICOS Associate Ecosystem Site DE-Har, UFR Code: HARTHM, 7.59814ºE, 47.93391ºN, 201 m) using an actively ventillated and shielded psychrometer with a PT100 resistance thermometer based on the design of Frankenberger (1951). The psychrometer is operated 2m above ground level at the base of the 30m measurement tower. Quality controlled in-canopy air temperature data are available and aggregated at 10min, 30min, hourly, daily, monthly and yearly resolution for the year 2020. Average, minimum and maximum in-canopy air temperatures are provided on hourly, daily, monthly and annual scales. Characteristic hours and days are reported on daily, monthly and annual scales (e.g. summer days with T_max > 25ºC, hot days with T_max > 30º, desert days with T_max > 35ºC, tropical nights with T_min > 20°, frost days with T_min < 0ºC and ice days with T_max < 0ºC, all based on 00:00 - 24:00 UTC). Detailed information on gap-filled data is provided. Note: All times are provided in UTC, not local time. For more details read `HARTHM_2020_AirTemperature_MetaData.txt`. Reference: Frankenberger E. (1951): Untersuchungen über den Vertikalaustausch in den unteren Dekametern der Atmosphäre, Ann. Meteorol. 4, 358–374. Version 1.1 changes: corrects an error in the time-axis of the file "..._Air_Temperature2m_10_min_UTC.csv", where previously the file would only contain reasonable values until August-15, 23:50. Other files were unaffected by this. displays times according to ISO 8610 to unambiguously identify that all times are given in UTC. Further, the column headers for the time periods have been changed to "From" and "To" to indicate the start and end of the aggregation periods.

COPYRIGHT Creative Commons Attribution 4.0 International. Copyright Albert-Ludwigs-Universität Freiburg, Professur für Umweltmeteorologie, Werthmannstrasse 10, Freiburg, Germany. CREATOR This work was created by the University of Freiburg, Germany. ATTRIBUTION The site is operated as part of the Integrated Carbon Observation System (ICOS). Instruments and sensors in the dataset were operated by the Chair of Environmental Meteorology, University of Freiburg, Germany. DISCLAIMER The use of the work is at the user's own risk. The authors and/or the involved institutions, accept no liability for material or non-material damage arising from the use or non-use or from the use of incorrect or incomplete information in this work. The author and/or the involved institutions are not responsible for any use that may be made of the information in this work. The legal provisions remain unaffected. MATERIAL NOTICE The notices cover data in databases, text and images contained in the work. MATERIAL URI Hartheim Forest Research Site DE-Har in the ICOS Carbon Portal