How often home values are really measured
Home value data always describes the past. Not because anyone is careless, but because of how a sale actually happens. Following one transaction through the pipeline explains the entire lag.
The pipeline
- Agreement. Buyer and seller settle on a price. This is the moment the market actually spoke, and it is invisible to everyone outside the deal.
- Closing. Thirty to sixty days later, typically. The price is now fixed but was set at step one, weeks ago.
- Recording. The deed is filed with the county. Days to weeks, and wildly variable by jurisdiction.
- Collection. Data aggregators pull county records on their own schedules.
- Publication. The index provider needs a full period of data, then computes, checks, and releases it.
By the time a sale appears in a published index, the negotiation that set the price can easily be four to six months in the past. Every step is a real requirement. None of it is slack that could be squeezed out.
What the different sources actually offer
Roughly, from fastest and noisiest to slowest and most solid:
- Listing prices. Available immediately. They are asks, not sales, and in a soft market the gap between the two is the whole story.
- Local board reports. Monthly, a few weeks behind. Usually median sale price, which is subject to the mix problem described in how an index works.
- Commercial automated valuations. Updated frequently, often weekly. The freshness is partly real and partly model smoothing between actual data points.
- Repeat sales indices. Monthly or quarterly, one to several months behind, then revised. The slowest and the most defensible.
Where this site sits
We use the FHFA All-Transactions House Price Index, which is quarterly. The release currently loaded is 2026 Q1, and every report on the site says so on its face.
That is the slow end of the range, deliberately. A quarterly government index built on millions of repeat transactions is not going to tell you what happened last month. It is going to be right about what happened last year, which for tracking your own home over time is the more useful property.
Revisions are a feature. Repeat sales indices get revised as late transactions arrive. A figure published for one quarter can shift slightly in the next release. That is the index correcting itself with better information, and a source that never revises is a source that is not looking.
Why weekly updates are mostly not what they seem
A tool that refreshes your home value every week is not receiving weekly evidence about your home. Sales in your immediate area do not happen weekly. What is usually changing is the model's interpolation between real data points, plus occasional genuine new inputs.
The movement looks like precision. Much of it is smoothing. We would rather update your report when the underlying measurement genuinely changes, and tell you which release produced the number, than manufacture the appearance of freshness.
What this means practically
If the market turned three months ago, no source has fully caught it yet, including ours. If you are tracking your home over years, the lag is irrelevant. If you are trying to time something to the month, no free data source is going to get you there, and you want a local professional watching live listings instead.