Why this exists, and how it is built.
Plain-English methodology. Every number on the site cites its agency, dataset, and vintage. When data isn't available for a peril or metro, we say "not available" instead of imputing.
The big number that gets cited everywhere
The headline — "tens of millions of Americans relocating internally due to climate by mid-century" — is a synthesis of several federal and academic projections. The defensible underlying data points:
- First Street Foundation, 9th National Risk Assessment (2023). ~3.2 million Americans have already relocated out of flood-risk areas; an additional ~50 million live in census blocks with material climate-risk exposure that may face property-value impairment.
- US Census Bureau ACS migration flows (2022). CA net out-migration ~318K; FL net out-migration ~50K. Heavy destination concentration in TN, TX, ID, NC, AZ.
- EDF / Rebuild By Design (2022). ~13 million Americans projected to be directly displaced by sea-level rise alone by 2100 under intermediate-high scenarios.
- USDA Economic Research Service (2023). County-level out-migration from Sierra Nevada counties post-2017–2020 fire seasons.
The "tens of millions" framing is a directional synthesis, not a single citation. The exact methodology is documented here so you can interrogate it.
How our climate risk scoring works
Six perils per metro, each scored 0-100 from a federal source. Per-peril sources:
| Peril | Source agency | Dataset | Vintage |
|---|---|---|---|
| Wildfire | USFS / Pyrologix; CAL FIRE FRAP | Wildfire Risk to Communities; Fire Hazard Severity Zone maps | 2020 release, refreshed 2024 |
| Hurricane | NOAA NHC | HURDAT2 + Historical Hurricane Tracks | Through 2024 season |
| Drought | USDA / NDMC / NOAA | US Drought Monitor | Weekly through 2024-12-31 |
| Sea-level rise | NOAA Office for Coastal Management | SLR Viewer (intermediate-high) | 2022 model |
| Water stress | WRI / USGS | Aqueduct Water Risk Atlas v4 baseline water stress | 2023 release |
| Extreme heat | NOAA NCEI | 1991-2020 US Climate Normals | 1991-2020 normals |
Blended score weights documented in src/lib/climate_risk.ts: hurricane and
wildfire 25% each (largest carrier-withdrawal driver 2020-2024); sea-level rise and
water stress 15% each; drought and extreme heat 10% each. Re-weighting is straightforward
and documented openly so practitioners can argue with it.
How our insurance market data works
Per-state availability + premium-pressure inputs:
- Florida OIR — Property Insurance Stability Report (quarterly) + Citizens Property Insurance Corporation monthly policy count + rate filings via iPortal.
- California DOI — FAIR Plan annual report + Sustainable Insurance Strategy regulatory package + non-renewal moratoria orders.
- Texas Department of Insurance — market-conduct data + TWIA 2024 annual report.
- North Carolina Department of Insurance + NC Rate Bureau filings + NCIUA 2023 annual report.
- Idaho, Arizona, Tennessee DOI rate-filing dockets.
- NAIC Homeowners Insurance Report (cross-state premium comparison).
How our cost-of-living + tax data works
- Median home price / rent. Zillow ZHVI / ZORI metro-level 2024-Q4.
- Median household income. US Census ACS 5-year 2019-2023, table S1901.
- Income tax. Tax Foundation State Individual Income Tax Rates 2024.
- Property tax. Tax Foundation effective rate (Property Taxes Paid as % of Owner-Occupied Housing Value), 2024 release using ACS 2022.
- Regional CPI. BLS regional CPI-U 12-month change, Dec 2024.
What we do not invent
Every number on this site cites its source and vintage. When data is unavailable for a particular peril or metro, we say "not available" rather than imputing. Tax-swing illustrations are explicitly labeled illustrative — applying statewide averages to user-supplied income/home-value inputs is decision-support, not a tax projection.
Sources we deliberately do not cite: GreatSchools / Niche school ratings (we cite state-published assessment data), climate-risk aggregators like ClimateCheck / RiskFactor (we cite underlying federal datasets), or news reporting on climate events (we cite the originating agency directly).
What we are not
We are not a brokerage, not an insurance carrier, not a tax preparer. We are a concierge service that unifies discovery + routes qualified next steps to licensed partners with full FTC affiliate disclosure. Binding actions happen with the licensed professional we route you to.
Founder posture
Migration Concierge is operated by a founder who has spent fifteen years in measurement-economics, consumer marketing analytics, and prediction-market work. The operator's calibration discipline is documented elsewhere; here it shows up as: we do not pre-write conclusions, we surface null findings honestly, and we will tell you when the move is not the right call for your household.
How to challenge a number on this site
Email concierge@migrationconcierge.com with the page, the claim, the source you believe is more current, and we will respond within 5 business days. We publish corrections at the article footer with a dated edit note.