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Data staleness — when to re-check zipradar before making a decision

zipradar timestamps every page. The data is as fresh as the upstream regulator publishes — which varies wildly by dataset. Here's when to trust the snapshot and when to verify direct.

Published 2026-04-25 · Last reviewed 2026-09-24 · methodology

Refresh cadence by dataset

Daily, upstream: county recorders post deed filings, usually within a day of recording. zipradar does not host deed counts yet; use the recorder's portal.

Rolling, upstream: agencies submit to the FBI Crime Data Explorer on their own schedules. zipradar does not host crime figures yet; use the FBI's explorer.

Quarterly: EPA SDWIS, FEMA NFHL, EPA LCRR (lead). New violations + map revisions process every 90 days.

Annual: air quality (EPA AQS county summary, currently 2025). For the hourly reading, go to airnow.gov.

Annual: NCES CCD school data (released following October for prior school year). 12-18 months lag.

Annual: County assessor reassessments (most jurisdictions). Tax bills typically generated November.

Decadal+: EPA Radon Map (1993 baseline). Newer state radon programs supplement.

When zipradar's snapshot is good enough

Browsing neighborhoods, narrowing search: any-time freshness fine.

Initial assessment of flood/wildfire/water risk: quarterly is plenty.

Choosing between metros: schools/property tax annual is fine.

Crime trend reading: weekly UCR is fresh enough to spot direction.

When to verify with the primary source

Closing on a house this week: re-check FEMA NFHL at fema.gov for your specific address (NEW LOMAs may have been issued).

Pulling permit for major renovation: re-check zoning at the planning department TODAY (rezonings happen).

Filing flood insurance claim: today's NFIP policy form is the truth, not zipradar's quarterly snapshot.

Disputing a tax assessment: pull the current bill from the assessor directly.

Health emergency / outdoor activity in wildfire season: airnow.gov real-time is the source, not zipradar's hourly cache.

How zipradar flags staleness

Every page shows 'Last verified YYYY-MM-DD' — that's the federation refresh, not the upstream source's last update.

Where the upstream regulator hasn't published recent data, we say so explicitly (don't silently serve old data).

Methodology page documents the federation refresh schedule per dataset.