Cook County Parcel Sales from 1999 to Present with Deed and Price Details

Parcel sales for real property in Cook County, used by the Assessor's Office to model fair market values. The data spans from 1999 to the present and includes 20 columns such as sale price, buyer and seller names, deed type, and property class. Records are updated monthly by the Cook County Assessor's Data Department, though sales are reported on a lag.

Use Cases

• Model property sale prices using sale_price, class, township_code, and neighborhood_code from 20 available columns.
• Analyze transaction types and frequency using sale_deed_type, sale_type, and sale_date from 20 available columns.
• Identify multi-parcel transactions and buyer/seller patterns using is_multisale, num_parcels_sale, sale_buyer_name, and sale_seller_name from 20 available columns.
• Recreate historical data filters using sale_filter_less_than_10k, sale_filter_deed_type, and sale_filter_same_sale_within_365 from 20 available columns.

Strengths

• Contains 20 columns of detailed transaction data, including sale_price, deed types, and participant names.
• Time series coverage from 1999 to the present, updated monthly.
• Includes documented filtering flags (e.g., sale_filter_less_than_10k) for data transparency.

Limitations

• Row count is unknown, which may limit suitability assessment.
• Sales data is reported on a lag, with records potentially populating months after the official recording date.
• Description notes the data likely includes non-arms-length transactions despite some filters.

Provenance

Source

Cook County Assessor's Office via datacatalog.cookcountyil.gov

Collection Method

Collected from recorded sales documents; preparation details are documented in the Assessor's Standard Operating Procedures for Open Data on GitHub.

Time Range

1999 to present

Freshness

Last updated 2026-04-01 14:55:38; updated monthly with a reporting lag.

Geography

Cook County, Illinois, USA