Records Broken on August 21, 2026
US weather stations that set a new daily high- or low-temperature record on August 21, 2026, measured against 55+ years of NOAA history.
How unusual was this?
STAMPEDE PASS, WA broke a heat record that had stood since 1970 — 56 years. The old mark was 81°F; the new one is 86°F.
Biggest Heat Records
Records by State
How we count records: A station sets a daily record when its high or low for the date beats every prior reading at that station for the same calendar day. We only count stations with at least 30 years of history for that day and filter readings flagged by NOAA's quality-control process. Data: NOAA NCEI GHCN-Daily. Recent days may rise as late-reporting stations are added.
How we get “expected”: If the climate were stable, a station with n prior years of history for a date would set a new record on that date with probability 1/(n+1) — today's reading is equally likely to land at any rank among the n+1 observations. Summing that across every eligible station gives the number of records a stable climate would produce. On this date that pool was 3,136 stations for highs and 3,126 for lows. No climate model is involved — it is arithmetic on the station count.
What the multiple is not: Nearby stations break records together, so a single day's total varies far more than independent counting would suggest. Treat the multiple as a description of the day, not a significance test. Records are measured against each station's own history since 1970, not all-time state or national marks.