Where the numbers on this site come from and how we calculate them
Every figure published on HistoClima comes from official Met Office weather station measurements and is automatically verified before publishing. This page explains the sources, the method and the rules we never break.
UK data comes from the Met Office MIDAS (Integrated Data Archive System) network: historical daily series per station, with the longest record starting in 1873 at Stornoway Airport and most stations reporting from the early 20th century onward. Data is published under the Open Government Licence (OGL) v3.0, freely reusable with Met Office attribution.
Each page states the specific station covering the location and the real period of its series. Wind and humidity are not present in the MIDAS daily extract, so HistoClima only publishes temperature (min/max/mean) and precipitation figures for the UK.
Records, streaks of consecutive days, frequencies and trends are calculated by traversing the complete historical series of the station, never from single data points.
A zero is a real measurement (the event did not happen that year), not a missing value; 'not available' is only shown when the station did not measure.
Every page passes an automatic control gate: every figure in the text must exist in our measurement database. Language models help us write the text, but never calculate or invent values — a page whose figures do not match the database is not published.
Verified historical data covers up to 31 December 2024. A recent layer from the Met Office MIDAS Open dataset is ingested weekly to keep the site current; historical pages are regenerated periodically to incorporate the latest verified series.
HistoClima publishes measurement data with a declared source (Met Office MIDAS), station and period. When citing our figures, include the location and the period they refer to. The content index is at /llms.txt and in the sitemap.
Sources: Met Office MIDAS (official data, Open Government Licence v3.0). Own analysis over the full series.