Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
Eurostat, the Statistical Office of the European Union
1.2. Contact organisation unit
E5: Energy Statistics
1.3. Contact name
Restricted from publication
1.4. Contact person function
Restricted from publication
1.5. Contact mail address
European Commission - Eurostat
Unit ESTAT.E.5: Energy
L-2920 Luxembourg
1.6. Contact email address
Restricted from publication
1.7. Contact phone number
Restricted from publication
1.8. Contact fax number
Restricted from publication
2.1. Metadata last certified
25 October 2024
2.2. Metadata last posted
25 October 2024
2.3. Metadata last update
25 October 2024
3.1. Data description
Heating degree day (HDD) index is a weather-based technical index designed to describe the need for the heating energy requirements of buildings. Cooling degree day (CDD) index is a weather-based technical index designed to describe the need for the cooling (air-conditioning) requirements of buildings.
HDD and CDD are derived from meteorological observations of air temperature, interpolated to regular grids at 25 km resolution for Europe. Calculated gridded HDD and CDD are aggregated and subsequently presented on NUTS-3 level.
This dataset includes monthly data as published by the Joint Research Centre's AGRI4CAST Resources Portal (Note that Eurostat is not the producer of the monthly data, but is only re-publishing them). Annual data are calculated as sum of monthly data by Eurostat.
Heating Degree Days (HDD) index: the severity of the cold in a specific time period taking into consideration outdoor temperature and average room temperature (in other words the need for heating). The calculation of HDD relies on the base temperature, defined as the lowest daily mean air temperature not leading to indoor heating. The value of the base temperature depends in principle on several factors associated with the building and the surrounding environment. By using a general climatological approach, the base temperature is set to a constant value of 15°C in the HDD calculation.
If Tm ≤ 15°C Then [HDD = ∑i(18°C - Tim)] Else [HDD = 0] where Tim is the mean air temperature of day i.
Examples: If the daily mean air temperature is 12°C, for that day the value of the HDD index is 6 (18°C-12°C). If the daily mean air temperature is 16°C, for that day the HDD index is 0.
Cooling degree days (CDD) index: the severity of the heat in a specific time period taking into consideration outdoor temperature and average room temperature (in other words the need for cooling). The calculation of CDD relies on the base temperature, defined as the highest daily mean air temperature not leading to indoor cooling. The value of the base temperature depends in principle on several factors associated with the building and the surrounding environment. By using a general climatological approach, the base temperature is set to a constant value of 24°C in the CDD calculation.
If Tm ≥ 24°C Then [CDD = ∑iTim - 21°C)] Else [CDD = 0]where Tim is the mean air temperature of day i.
Examples: If the daily mean air temperature is 26°C, for that day the value of the CDD index is 5 (26°C-21°C). If the daily mean air temperature is 22°C, for that day the CDD index is 0.
These calculations are executed on a daily basis, added up to a calendar months and subsequently to calendar years.
3.5. Statistical unit
Gridded meteorological data from temperature measuring stations.
3.6. Statistical population
The HDD and CDD estimates for the EU are based on observations from about 3000 weather stations across Europe.
3.7. Reference area
Annual and monthly data series cover the Member States of the European Union and the EU aggregate.
3.8. Coverage - Time
Data are available since January 1975, for Cyprus since January 1978.
3.9. Base period
Not applicable.
HDD and CDD data are presented as ˚C temperature sums.
The reference period is the calendar month.
6.1. Institutional Mandate - legal acts and other agreements
Article 22 of Regulation (EU) No 1306/2013 on the financing, management and monitoring of the common agricultural policy.
6.2. Institutional Mandate - data sharing
This dataset includes monthly data as published by the Joint Research Centre's AGRI4CAST Resources Portal. Note that Eurostat is not the producer of the monthly data, but only republishes them. Annual data are calculated as sum of monthly data by Eurostat.
7.1. Confidentiality - policy
Regulation (EC) No 223/2009 on European statistics (recitals 23-27, 31-32 and Articles 20-26) applies. It stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.
In line with the Community legal framework and the European Statistics Code of Practice Eurostat disseminates European statistics on Eurostat's website (see item 10 - 'Accessibility and clarity') respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably. The detailed arrangements are governed by the Eurostat protocol on impartial access to Eurostat data for users.
High regional comparability due to the harmonised methodology within all regions/countries.
15.2. Comparability - over time
High temporal comparability due to the harmonised methodology for all time periods.
15.3. Coherence - cross domain
Not applicable.
15.4. Coherence - internal
Comparable measurements systems following WMO standards ensure internal coherence; air temperature measurements are independent from one another.
Not available.
17.1. Data revision - policy
All data disseminated consist of data already disseminated by the JRC in the MARS Meteorological Database inside the Agri4Cast resource.
The revision policy is therefore effectively the revision policy applied by the JRC for MARS.
17.2. Data revision - practice
The revision practice effectively corresponds to the revision practice of the JRC for the MARS Meteorological Database inside the Agri4Cast resource – but with a revision periodicity corresponding to the Eurostat retrieval schedule (once per year).
Each year, when data are retrieved by Eurostat from MARS, the already disseminated data are updated. In practice, JRC revisions of already published MARS data are very rare.
The data collection process is established and managed by the Joint Research Centre.
18.4. Data validation
Data are based on annually validated and consolidated JRC-MARS gridded meteorological data. These data are checked for data gaps, errors, or dubious values for which corrections are acquired. Subsequent revisions include more or better data.
18.5. Data compilation
Not available.
18.6. Adjustment
Not available.
This dataset includes monthly data as published by the Joint Research Center's AGRI4CAST Resources Portal (Note that Eurostat is not the producer of the monthly data, but is only republishing them).
Heating degree day (HDD) index is a weather-based technical index designed to describe the need for the heating energy requirements of buildings. Cooling degree day (CDD) index is a weather-based technical index designed to describe the need for the cooling (air-conditioning) requirements of buildings.
HDD and CDD are derived from meteorological observations of air temperature, interpolated to regular grids at 25 km resolution for Europe. Calculated gridded HDD and CDD are aggregated and subsequently presented on NUTS-3 level.
This dataset includes monthly data as published by the Joint Research Centre's AGRI4CAST Resources Portal (Note that Eurostat is not the producer of the monthly data, but is only re-publishing them). Annual data are calculated as sum of monthly data by Eurostat.
25 October 2024
Heating Degree Days (HDD) index: the severity of the cold in a specific time period taking into consideration outdoor temperature and average room temperature (in other words the need for heating). The calculation of HDD relies on the base temperature, defined as the lowest daily mean air temperature not leading to indoor heating. The value of the base temperature depends in principle on several factors associated with the building and the surrounding environment. By using a general climatological approach, the base temperature is set to a constant value of 15°C in the HDD calculation.
If Tm ≤ 15°C Then [HDD = ∑i(18°C - Tim)] Else [HDD = 0] where Tim is the mean air temperature of day i.
Examples: If the daily mean air temperature is 12°C, for that day the value of the HDD index is 6 (18°C-12°C). If the daily mean air temperature is 16°C, for that day the HDD index is 0.
Cooling degree days (CDD) index: the severity of the heat in a specific time period taking into consideration outdoor temperature and average room temperature (in other words the need for cooling). The calculation of CDD relies on the base temperature, defined as the highest daily mean air temperature not leading to indoor cooling. The value of the base temperature depends in principle on several factors associated with the building and the surrounding environment. By using a general climatological approach, the base temperature is set to a constant value of 24°C in the CDD calculation.
If Tm ≥ 24°C Then [CDD = ∑iTim - 21°C)] Else [CDD = 0]where Tim is the mean air temperature of day i.
Examples: If the daily mean air temperature is 26°C, for that day the value of the CDD index is 5 (26°C-21°C). If the daily mean air temperature is 22°C, for that day the CDD index is 0.
These calculations are executed on a daily basis, added up to a calendar months and subsequently to calendar years.
Gridded meteorological data from temperature measuring stations.
The HDD and CDD estimates for the EU are based on observations from about 3000 weather stations across Europe.
Annual and monthly data series cover the Member States of the European Union and the EU aggregate.
The reference period is the calendar month.
Not applicable.
HDD and CDD data are presented as ˚C temperature sums.
