Understanding & Applying Time Trends

Time Trends Overview

Time trending is the process of updating property sale prices to reflect market conditions as of a certain date. In Colorado, time trends are calibrated to reflect market values as of June 30th of even-numbered years (e.g., June 30th, 2024), known as the “reappraisal date”. 

Time trends are developed in the Assessor’s office by applying statistical analysis to market sales that occurred prior to the reappraisal date. A minimum of 18 months of sales data, and a maximum of 60 months of sales data, are considered in the analysis, per § 39-1-104(10.2)(d), C.R.S. Larimer county publishes time trend data for the full 60-month period prior to the reappraisal date.

Finding Time Trend Data

Time trend data are typically published shortly before May 1st of odd numbered years and reflect market conditions as of June 30th of the prior year. Time trend data are categorized by property type and are available for download on the Assessor site.

Each downloadable time trend file includes a time period representing the month and year of the property sale (i.e., “DATE”), the time trend adjustment factor (i.e., “TMADJ”), and other stratifications (e.g., neighborhood, economic area, etc.) where applicable.

Example Time Trend Application

The time trend adjustment is multiplied by the original sale price to calculate the time-adjusted sale price. 

For example, consider a single-family residential home in Fort Collins Neighborhood 18933 sold in June 2021 for $525,000. The time trend adjustment for homes sold in June 2021 in this neighborhood is 1.1687 (as highlighted in the table above). Hence, the time-adjusted sale price of this property is $613,568 (calculation graphic shown below).

Original Sale Price multiplied by Time Adjustment Factor equals Time Adjusted Sale Price:
$525,000 × 1.1687 = $613,568