How We Count Weather Records and Why We Differ From NOAA

We count a weather record whenever a station’s daily value passes, or equals, the highest or lowest value that station has measured for that element, on that calendar day, in that month or ever. Our numbers can differ slightly from NOAA’s because we use more stations, keep ties as separate entries and mark recent records as provisional.

What counts as a record

Each station has up to seven kinds of record: highest maximum temperature, lowest maximum temperature, highest minimum temperature, lowest minimum temperature, highest daily rainfall, highest daily snowfall and greatest snow depth. Each kind can be a record for a calendar day (say every 14 July on file), for a month, or for all time at that station. The same observation can be all three at once. We store it once, under the broadest timescale it breaks, so a value that sets an all-time record is not also counted as a daily one. Our explainer on what a weather record is walks through the definitions with examples.

Which stations qualify

A station is eligible for an element once it has at least 30 years in which more than 182 days have a complete observation for that element. The test is applied as of each date, not as of today, so a station only starts producing records once it has qualified for that element. NOAA’s Daily Weather Records tool applies the same test, which keeps the two comparable.

This build reads 42,764 stations in 181 countries, and the ledger holds 0 record events. Data is current to 12 October 2026.

Ties are entries too

When a new value equals the standing record at the recorded precision, that is a tie. We keep ties as their own entries and label them, and they carry half the weight in our significance score. See what a record tie is for why precision matters here.

Why totals differ from NOAA

Three choices explain almost every gap.

1. Station set. We use every eligible GHCN-Daily station worldwide. NOAA’s tool works from a subset.
2. Ties and timescales. We show ties separately and count one event per observation. Tools that count each timescale separately report larger totals for the same day.
3. Provisional data. Records set in the last 60 days are labelled provisional and reprocessed daily. Any withdrawal or change goes into the corrections log.

None of these is an error on either side. They are different, documented rules. The full rule set is on the methodology page, and every dataset is credited on the sources page.

What to read next

The ratio of record highs to record lows is the steadiest use of these counts. For how long records survive, see the oldest records still standing.