Sources and methodology
Find out what the figures measure and what to consider when comparing them.
What the figures measure
INE population series count residents at a specific date. For example, the annual figure for 2025 refers to 1 January 2025. Nationality breakdowns do not indicate birthplace. The annual census and ECP appear as separate series.
How we calculate shares and changes
To calculate a municipality’s share of the provincial population, we divide counts from the same date and data release. Change is the difference between the selected year and the earliest available year. Percentage change divides that difference by the initial count; we omit it when that count is zero. These calculations show how much the population changed, but do not explain why.
Which places can be compared
We show a census-section map when its boundaries match the selected date. IGN administrative boundaries provide current context, but do not establish where boundaries were in earlier years. We retain the municipal counts published by INE; boundary changes can affect comparisons between years. Map colour shows resident counts, not population density or personal risk.
Missing data and dates
A dash means a value is unavailable. We distinguish a count of zero from a value withheld for statistical confidentiality or an area without coverage. The date a figure refers to, the date its source published it and the date it entered the atlas can differ. If we do not know the source publication date, it is marked as not recorded.
Read and download the data behind a view
Download the values, your selection and source references as a JSON file. A view’s link keeps the version you consulted for as long as it remains publicly available.
Current limitations
These figures describe places and groups of people; they cannot establish an individual’s characteristics. Differences between sources, dates or boundaries can prevent direct comparison.
Population dates and coverage
The annual census and Continuous Population Statistics (ECP) are separate sources. Municipal ECP covers municipalities with at least 100,000 residents and provincial capitals. Quarterly Spain and island series are explored separately, including the provincial totals for both archipelagos. Each view retains its reference date, source status and published version. Other quarterly regional and provincial coverage remains pending.
Population is a count at a specific date; publication does not require the year to have ended. Each source keeps its reference date, coverage and provisional or final status. A July figure for a province cannot stand in for a July figure for each municipality.