Editorial Policy & Corrections
What PlainClimate publishes
PlainClimate presents the U.S. climate normals published by the NOAA National Centers for Environmental Information (NCEI) for the 1991–2020 period: 30-year average temperatures, precipitation, snowfall, frost dates, growing-season length, and heating/cooling degree days for 6,861 station-mapped U.S. locations drawn from 15,492 weather stations. We do not generate weather forecasts and we do not produce original temperature measurements.
How the pages are built
Every figure on this site is compiled programmatically from NOAA's public-domain dataset by our ETL (extract-transform-load) pipeline, then rendered live from our database. We do not hand-key values, and, to be plain about it, a human editor does not individually review each of the thousands of city and state pages. What PlainClimate does own is the methodology: which NOAA stations map to each city, how monthly normals roll up to annual figures, the comfort-score formula, the page templates, and this corrections process. When we describe data as "compiled by PlainClimate," that means accountability for the method and framing, not a claim of manual line-by-line review.
The comfort score
The 1–100 comfort score is a PlainClimate composite, it is not a NOAA metric. It combines temperature moderation, low extreme-weather frequency, moderate precipitation, and (where hourly data exist) humidity into a single index. It reflects broad preference patterns and is intended for orientation, not as an authoritative livability ruling; individual tolerance for heat, cold, rain, and humidity varies widely. See the methodology for the full derivation.
Editorial standards
- Derived values, like the comfort score, are labeled as our own analysis, distinct from NOAA's raw source figures.
- No invented data. Where a value is unavailable for a city or station, the page says so; we never substitute an estimate for a missing figure.
Accuracy & corrections
Because the data flows from a single authoritative source through a documented pipeline, most errors would be systematic (a mapping or formula issue) rather than one-off typos. Here is how a reported issue becomes a fix:
- Report. Tell us the page URL and the value that looks wrong via the contact page.
- Verify. We trace the figure back to NOAA's source data and our pipeline's transformation of it.
- Fix at the source. If the error is ours, we correct the pipeline or station mapping, not just the one page, so every affected city or state heals at once.
- Note on the next rebuild. Methodology or formula corrections are dated with the rebuild that applied them.
Data changelog
Dated corrections and data refreshes actually applied to this site. Every entry below is corroborated by the pipeline's build metadata or the site's revision history, we never backfill or invent changelog entries.
- - Full data rebuild from the NOAA source archives. Comfort-score methodology correction: cities with fewer than two of the three optional components (precipitation moderation, extreme-weather frequency, humidity) now show N/A instead of a silently imputed midpoint value.
- - Retired the warming-anomaly lookup estimator: the underlying dataset (30-year normals) cannot support per-city current-anomaly estimates, so the tool was removed rather than kept on an unsupported basis.
- - Display fix: the national comfort-score histogram silently dropped the 26 cities with a perfect 100 score from its top bucket (chart display only; no underlying values affected).
- - Four display-honesty fixes from an independent review: percentiles capped at 99% (no city can be "milder than 100% of cities"); missing frost dates no longer render as "N/A" mid-sentence; "seasonal snowfall possible" no longer shown where recorded snowfall is zero; the national comfort-median marker now uses the computed median instead of a stale hardcoded value.
- - The hottest-cities ranking was rebuilt to render directly from the database after the previous hand-entered table was found internally inconsistent; a "2026 data" badge was corrected to the real 1991–2020 vintage.
Independence
PlainClimate is an independent publisher and is not affiliated with NOAA or any U.S. government agency. We display advertising (see our privacy policy), which never influences how the underlying public data is reported.