AndreaBozzo/ceres-open-data-index huggingface dataset:
ccgisdata - Cook County Cooling Centers

Municipalities around Cook County have opened cooling centers for area residents as temperatures start to rise. Residents who need to seek shelter should contact the center first to verify it is open. This dataset will be no longer updated on May 1, 2019. Please refer to this link for future updates: https://datacatalog.cookcountyil.gov/dataset/Cook-County-Cooling-Centers-Map/dnn9-esge
CC Municipal Incorporation Inventory

Department of GIS sponsored Municipal Incorporation Inventory (MII) project. The following agencies participated in this project: The Cook County Recorder of Deeds, Cook County Emergency Telephone System Board, Cook County Circuit Court, Archives Department, Cook County Department of Transportation and Highways, the Cook County Clerk’s Office and the Illinois State Archives Office of the Secretary of State. The data is not guaranteed to be accurate, correct, or complete. Information provided should not be used as a substitute for legal, business, tax, or other professional advice. The recipient/viewer should contact appropriate regulating agencies to determine accuracy or suitability of the data for a particular use.
Campaign Contributions - Restricted Contractors

Under Cook County Ethics Code Section 2-585, campaign contributions to County elected officials are limited to $1,500 per calendar year if the contributor is currently doing or has done business with the County. The term "doing business" or "done business" is defined at "any one or any combination of sales, purchases, leases, or contracts to, from, or with the County or any County agency in excess of $10,000.00 in the previous four years." This dataset lists all vendors currently affected by these campaign contributions limited due to their current or past work with the County. Contribution limits apply to the listed vendor, its subsidiaries, parent company, or otherwise affiliated companies. Please note that this dataset may include separate entries for different divisions of the same company, its subsidiaries, parent company, or otherwise affiliated companies. While listed separately, they are considered a single entity/vendor subject to the County's contribution limit.
Businesses Registered with the Cook County Department of Revenue

This dataset includes all businesses currently registered with the Cook County Department of Revenue and subject to Amusement Home Rule, Dealer Use Home Rule, Diesel Home Rule, Firearm, Gasoline Home Rule, Liquor Home Rule, New Motor Vehicle Home Rule, Tobacco Wholesale, or Parking Home Rule taxes. The dataset does not include retail manufacturers. This data is updated monthly, but if up-to-the-minute accuracy is needed, contact the Department of Revenue at 312-603-6328.
Board of Ethics - Notices of Determination

By ordinance, the investigations and considerations by the Board of Ethics of potential violations of the Ethics Ordinance are confidential. County Code, § 2-592. As a matter of policy, the Board also maintains as confidential the identity of the requestors of advisory opinions. Board of Ethics Rules & Regulations, § 4.10. The Board, however, is undertaking to make its final determinations available to the public with such deletions as may be necessary to prevent disclosure of any information the Board determines to be confidential.
Board of Ethics - Advisory Opinions

By ordinance, the investigations and considerations by the Board of Ethics of potential violations of the Ethics Ordinance are confidential. County Code, § 2-592. As a matter of policy, the Board also maintains as confidential the identity of the requestors of advisory opinions. Board of Ethics Rules & Regulations, § 4.10. The Board, however, is undertaking to make its final determinations available to the public with such deletions as may be necessary to prevent disclosure of any information the Board determines to be confidential.
Assessor - Single and Multi-Family Improvement Characteristics

Single and multi-family (less than 7 units) property characteristics collected and maintained by the Assessor's Office for all of Cook County, from 1999 to present. The office uses this data primarily for valuation and reporting. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. This data is improvement-level - 'improvements' are individual buildings on a parcel. Each row in a given year corresponds to a building e.g. two rows for the same parcel in one year means a parcel has more than one building. Data will be updated semi-monthly. Rowcount and characteristics for the current year are only final once the Assessor [has certified the assessment roll] for all townships. Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated. NOTE: The Assessor's Office has recently changed the way Home Improvement Exemptions (HIEs) are tracked in its data. HIEs "freeze" a property's characteristics for a period of time with the intention of encouraging owners to improve their property without fear of assessment increases. Historically, the updated, "improved" characteristics were saved in a separate file. However, in more recent years, the improved characteristics are saved in the main characteristics file. As such, the records in this data set from before 2021 do NOT include HIE characteristic updates, while those after and including 2021 DO include those updates. For more information on HIEs, see the [Assessor's Data Department wiki]. For more information on how this data is used to estimate property values, see the [Assessor's residential modeling code] on GitHub. Township codes can be found [in the legend of this map]. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Residential Condominium Unit Characteristics

Residential condominium unit characteristics collected and maintained by the Assessor's office for all of Cook County, from 1999 to present. The office uses this data primarily for valuation, assessments, and reporting. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. This data is unit-level. Each 14-digit PIN represents one condominium unit. The first 10 digits of each PIN are the condominium building. Additional notes: * The Assessor's Office has historically not tracked any internal, unit-level characteristics for condominiums, including square footage, number of bedrooms, etc. In 2021, the office began to manually compile unit-level data from a variety of sources. The ultimate intention is to gather basic data on all condominium units in the county. * As such, unit square footage, building total square footage, and unit number of bedrooms are only available on a per-triad basis after 2021. Future data updates will add these features for other areas. * Condominiums are assessed based on their percentage of ownership. See the link below for more information on how this process works. The percentage of ownership for all units in a building should sum to 1. However, this may not always be the case in this data, since it does not include commercial units. * Condominium parcels can also be parking areas, storage units, or common areas. Identifying these units can be challenging, and they are not valued using mass appraisal. The Assessor's Office has an ongoing effort to clean up and identify these unit records. * Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. * Data will be updated semi-monthly. * Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated. * Rowcount and characteristics for the current year are only final once the Assessor [has certified the assessment roll] for all townships. For more information on how this data is used to estimate condominium unit values, see the [Assessor's condominium modeling code] on GitHub. Township codes can be found [in the legend of this map]. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Property Tax-Exempt Parcels

Parcels with property tax-exempt status across all of Cook County per tax year, from Tax Year 2022 on, with geographic coordinates and addresses. Properties of religious, charitable, and educational organizations, as well as units of federal, state and local governments, can be eligible for exemption from property taxes. The Illinois Department of Revenue (IDOR) ultimately grants qualified organizations with property tax exempt status, with additional administration by the Board of Review and/or Assessor. Learn more [here], and see the Assessor's guidance for religious organizations [here]. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Additional notes: * Parcel entroids are based on [Cook County parcel shapefiles]. * Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service. * Exempt status for parcels changes regularly depending on the use and owner of a given parcel. Please contact Assessor.Exempt@cookcountyil.gov if you need additional information about parcels excluded from this dataset. * Data will be updated semi-monthly. * This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values and property tax-exempt status for any given year are subject to change until [review and certification of values by the Cook County Board of Review], though there are a few rare circumstances where values may change for the current or past years after that. * Rowcount for a given year is final once the Assessor [has certified the assessment roll] all townships. * Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Permits

Historical permit data submitted by municipalities to the Cook County Assessor's Office. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Additional notes: * Almost all of the data in this dataset, such as address, estimated date of completion, work description, and permit amount, is data submitted by municipalities to the CCAO. The CCAO verifies or corrects the PIN number, determines whether the work is assessable, updates the status of CCAO workflows (e.g., open or closed), and sets the recheck year. * In addition to permits that are already closed, this dataset includes permits that are currently open or pending. These permits are not final and are subject to change. * Data will be updated semi-monthly. Rows are unique by the combination of "pin", "permit_number", and "date_issued". Job codes and improvement codes are not correct in all cases. Consider "work_description" to be the canonical description of the work that the permit describes. In many past cases permits have been submitted in irreconcilably different formats by different municipalities, or not at all. As such, this dataset does not represent the complete universe of permits in all municipalities, but rather represents the universe of permits that the CCAO knows about. Each row represents a parcel and a permit that is associated with that parcel. Permits may be associated with multiple parcels, and parcels may be associated with multiple permits. "date_issued" is more reliable than "date_submitted". Prefer "date_issued" when making temporal comparisons between parcels. Data for the current tax year may not yet be complete or final. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Parcel Universe (Current Year Only)

A current-year-only universe of Cook County parcels with attached geographic, governmental, and spatial data. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Additional notes: * Non-taxing district data is attached via spatial join (st_contains) to each parcel's centroid. * Tax district data (school district, park district, municipality, etc.) are attached by a parcel's assigned tax code. * Centroids are based on [Cook County parcel shapefiles]. * Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile). * Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service. * This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until [review and certification of values by the Cook County Board of Review], though there are a few rare circumstances where values may change for the current or past years after that. * Rowcount for a given year is final once the Assessor [has certified the assessment roll] all townships. * Data will be updated semi-monthly. * Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated. * Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. * Due to discrepancies between the systems used by the Assessor and Clerk's offices, tax_district_code is not currently up-to-date in this table. * There are currently two different sources of parcel-level municipality available in this data set, and they will not always agree: tax and spatial records. Tax records from the Cook County Clerk indicate the municipality to which a parcel owner pays taxes, while spatial records, also from the Cook County Clerk, indicate the municipal boundaries within which a parcel lies. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Parcel Universe

A complete, historic universe of Cook County parcels with attached geographic, governmental, and spatial data. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Additional notes: * Non-taxing district data is attached via spatial join (st_contains) to each parcel's centroid. * Tax district data (school district, park district, municipality, etc.) are attached by a parcel's assigned tax code. * Centroids are based on [Cook County parcel shapefiles]. * Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile). * Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service. * This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until [review and certification of values by the Cook County Board of Review], though there are a few rare circumstances where values may change for the current or past years after that. * Rowcount for a given year is final once the Assessor [has certified the assessment roll] all townships. * Data will be updated semi-monthly. * Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated. * Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. * Due to discrepancies between the systems used by the Assessor and Clerk's offices, tax_district_code is not currently up-to-date in this table. * There are currently two different sources of parcel-level municipality available in this data set, and they will not always agree: tax and spatial records. Tax records from the Cook County Clerk indicate the municipality to which a parcel owner pays taxes, while spatial records, also from the Cook County Clerk, indicate the municipal boundaries within which a parcel lies. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Parcel Sales

Update 10/31/2023: Sales are no longer filtered out of this data set based on deed type, sale price, or recency of sale for a given PIN with the same price. If users wish to recreate the former filtering schema they should set sale_filter_same_sale_within_365, sale_filter_less_than_10k, and sale_filter_deed_type to False. Parcel sales for real property in Cook County, from 1999 to present. The Assessor's Office uses this data in its modeling to estimate the fair market value of unsold properties. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Sale document numbers correspond to those of the Cook County Clerk, and can be used on the [Clerk's website] to find more information about each sale. NOTE: These sales are filtered, but likely include non-arms-length transactions - sales less than $10,000 along with quit claims, executor deeds, beneficial interests are excluded. While the Data Department will upload what it has access to semi-monthly, sales are reported on a lag, with many records not populating until months after their official recording date. Current property class codes, their levels of assessment, and descriptions can be found [on the Assessor's website]. Note that class codes details can change across time. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Parcel Proximity

Cook County 10-digit parcels with attached distances to various spatial features. When working with 10-digit Parcel Index Numbers (PINs) make sure to zero-pad them to 10 digits. Some datasets may lose leading zeros for PINs when downloaded. 10-digit PINs do not identify individual condominium units. Additional notes: * Centroids are based on [Cook County parcel shapefiles]. * Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile). * Attached spatial data does NOT all go back to 2000. It is only available for more recent years, primarily those after 2012. * This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until [review and certification of values by the Cook County Board of Review], though there are a few rare circumstances where values may change for the current or past years after that. * Rowcount for a given year is final once the Assessor [has certified the assessment roll] all townships. * Data will be updated annually as new parcel shapefiles are made available. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Parcel Addresses

Situs and mailing addresses of Cook County parcels. Used by the Assessor's office to mail assessment notices. This dataset was updated in March 2026 to include both owner and taxpayer information. Please note that owner name and mailing address is, to our knowledge, only intermittently updated in the ias source data. Users can use [Parcel Sales data] to query owner and seller names. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. Additional notes: * Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service. * Rowcount for a given year is final once the Assessor [has certified the assessment roll] all townships. * Data will be updated semi-monthly. For more information on the sourcing of attached data and the preparation of this dataset, see the [Assessor's Standard Operating Procedures for Open Data] on GitHub. [Read about the Assessor's 2025 Open Data Refresh.]
Assessor - Neighborhood Boundaries

Neighborhood polygons used by the Cook County Assessor's Office for valuation and reporting. These neighborhoods are specific to the Assessor. They are intended to represent homogenous housing submarkets, NOT Chicago community areas or municipalities. These neighborhoods were reconstructed from individual parcels using spatial buffering and simplification. The full transformation script can be found on [the Assessor's GitHub]. [Read about the Assessor's 2025 Open Data Refresh.]