# Source snapshot — heat-deaths story

Retrieved **8 November 2026** by [`fetch.mjs`](fetch.mjs) (from the download folder: `npm ci && node heat-deaths-src/fetch.mjs`, about five minutes because CDC WONDER asks for 15 seconds between requests). [`calculate.mjs`](calculate.mjs) checks the three CSVs' SHA-256 below and writes every number quoted in the post to `statistics.json`; `../heat-deaths-make-charts.mjs` builds the desktop and `-mobile.svg` charts from the same rows.

**Edition check (8 November 2026).** The NWS's 2025 national summary (`sum25.pdf`) and 2025 heat summary (`heat25.pdf`) were re-downloaded and are byte-identical to the copies the DataPressr dataset and draft were built from (SHA-256 `d88d5f83…7f92715` and `a1ebdd1a…0bd96588`; server `Last-Modified` 16 and 15 July 2026). The NWS hub page still labels 2025 "Preliminary"; no 2026 summary exists. CDC WONDER's latest final multiple-cause file is 2018–2024 (D157, "deaths occurring through 2024"); 2025 is available only in the provisional file (D176, "deaths occurring through October 24, 2026 as of November 1, 2026").

## National Weather Service

- **Publisher:** National Weather Service, *Summary of U.S. Natural Hazard Statistics*, one PDF per year, and *Heat Related Fatalities* per-state summaries, both linked from <https://www.weather.gov/hazstat/>.
- **Licence:** public domain as a US federal government work ([NWS disclaimer](https://www.weather.gov/disclaimer)). The figures are extracted from National Weather Service publications, which are not subject to copyright protection.
- **`nws-hazard-statistics.csv`** (788 rows; SHA-256 `b874942662a64bbbf7876c57cb3854b6507066e7cbaf7e7d60dbd1dd6c0169cb`): a copy of `data/hazard-statistics.csv` from the DataPressr dataset [us-natural-hazard-statistics](https://github.com/datasets/datapressr/tree/main/datasets/climate-and-environment/us-natural-hazard-statistics) at commit `c6366474c81a58e4e166c028d9488080142510e5`, extracted from the annual PDFs by its `build.ts` (archive retrieved 19 September 2026). One row per year and event type plus each year's own total row (`is_total`). Spot-checked against `pdftotext` output of the 1999, 2006, 2011, 2020, 2023, 2024 and 2025 PDFs for heat, cold, tornado and flash flood.
- **`nws-heat-deaths-arizona.csv`** (29 rows; SHA-256 `26ffb1e6662b8a2d0ade65c7f56cb03c9633d034a078adf41d5df6f73cbf3a6d`): a copy of `site/stories/heat-quiet-killer-src/heat-deaths-arizona.csv` from the same commit: per year, the total of the "Heat Related Fatalities by State and Location" table (`heat_all_states`) and its Arizona row (`arizona`; 0 where the table has no AZ row), extracted from `heat97.pdf`–`heat25.pdf` (retrieved 10 October 2026; the PDFs and their hashes are in that folder). Spot-checked here for 2005, 2016, 2019, 2020 and 2023. `calculate.mjs` and the chart builder stop unless every year's `heat_all_states` equals the national summary's heat row.

## CDC WONDER, Multiple Cause of Death

- **Publisher:** Centers for Disease Control and Prevention, National Center for Health Statistics. *Multiple Cause of Death 1999–2020* (D77), *Multiple Cause of Death, 2018–2024, Single Race* (D157) and *Provisional Mortality Statistics, 2018 through Last Week* (D176), on CDC WONDER, <https://wonder.cdc.gov/mcd.html>. Data from the National Vital Statistics System, compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program.
- **Licence and terms:** US federal government data, public domain. WONDER's data-use restrictions (accepted by `fetch.mjs` with `accept_datause_restrictions=true`) forbid attempts to identify individuals. WONDER's terms prohibit publishing statistics representing nine or fewer births or deaths, including rates based on those counts ([data-use restrictions](https://wonder.cdc.gov/datause.html)). WONDER suppresses counts of 1–9, including national counts. This package does not publish or reconstruct those small cells: it holds only national yearly counts for two overlapping groups (heat, cold), never their union or intersection, and `fetch.mjs` stops if any count is below 10 (the smallest is 309). See the [confidentiality section of the WONDER help](https://wonder.cdc.gov/wonder/help/mcd.html#Assurance%20of%20Confidentiality). Suggested citation form: Centers for Disease Control and Prevention, National Center for Health Statistics. Multiple Cause of Death on CDC WONDER Online Database. Accessed 8 November 2026.
- **Query:** each database's own request form, with defaults, except: group by year; "MCD - ICD-10 Codes" with any of the listed codes; totals shown. National only (the WONDER API does not serve location queries). See `fetch.mjs`.
- **`cdc-wonder-deaths.csv`** (60 rows; SHA-256 `1e19476e704c6c54b831bdfd906e23e5d5992a544a7a5c61b9d9edcf867d1f28`): `database`, `database_label`, `vintage`, `status` (final/provisional), `year`, `group` (heat, cold), `icd10_mcd_codes`, `deaths`. D77 for 1999–2020, D157 for 2018–2024, D176 for 2025 only. D77 and D157 agree exactly for both groups in 2018–2020; `calculate.mjs` checks this and uses D77 to 2017 and D157 from 2018. Not hash-checked on re-fetch: NCHS reissues files, so a later run may differ.

## Context documents cited, not snapshotted

- NWS Instruction 10-1605, *Storm Data Preparation*, 26 July 2021, <https://www.weather.gov/media/directives/010_pdfs/pd01016005curr.pdf> (sections 2.6, A-5 Cold/Wind Chill, A-12 Excessive Heat, A-20 Heat).
- Gasparrini A, et al. "Mortality risk attributable to high and low ambient temperature: a multicountry observational study." *Lancet* 2015;386(9991):369–375, <https://pubmed.ncbi.nlm.nih.gov/26003380/> (384 locations in 13 countries; pooled, 7.29% of deaths attributable to cold, 0.42% to heat; for the USA, 135 cities, 1985–2006, 5.51% cold and 0.35% heat, Table 2 of the full text <https://pmc.ncbi.nlm.nih.gov/articles/PMC4521077/>).
- Liu M, et al. "Cold-Related Deaths in the US." *JAMA* 2025;333(5):427–429, <https://jamanetwork.com/journals/jama/fullarticle/2828342> (40,079 deaths 1999–2022; codes X31, T68, T69; age-adjusted rate 0.44 to 0.92 per 100,000).
- Berko J, Ingram DD, Saha S, Parker JD. "Deaths attributed to heat, cold, and other weather events in the United States, 2006–2010." *National Health Statistics Reports* 76, 2014, <https://www.cdc.gov/nchs/data/nhsr/nhsr076.pdf> (3,332 heat, 6,660 cold; its cold definition omits T69).
- Weinberger KR, et al. "Estimating the number of excess deaths attributable to heat in 297 United States counties." *Environmental Epidemiology* 2020;4(3):e096, <https://pubmed.ncbi.nlm.nih.gov/32613153/> (5,608 a year, 1997–2006; the counties hold about 62% of the population per the full text).
- Maricopa County Department of Public Health, 2023 heat deaths report (March 2024), 645 heat-associated deaths, as reported by KJZZ, <https://www.kjzz.org/2024-03-13/content-1874049-maricopa-county-reported-645-heat-related-deaths-2023-700-increase-decade-ago>. The county's own release, <https://www.maricopa.gov/CivicAlerts.aspx?AID=3222>, refuses automated requests.