The debate around the timing of the IPCC’s Seventh Assessment Report is, on the surface, about deadlines. When the Intergovernmental Panel on Climate Change meets in Addis Ababa in October 2026, one of the questions under discussion will be whether the three AR7 Working Group reports can be completed in time to inform the 2028 Global Stocktake.
But behind that discussion is a much more practical issue: good decisions depend on having enough historical evidence to understand what “normal”, “unusual” and “extreme” actually mean.
For companies managing energy assets, infrastructure, transport networks or other weather-sensitive operations, that same principle applies every day. And unlike a global assessment cycle, historical weather data can already be used now.
Why a long weather record matters
A few recent years can be misleading. A warm winter, an unusually wet season or a period of low wind generation may look exceptional until it is compared with a much longer history.
A deep historical record helps answer practical questions:
- Has this happened here before?
- How unusual are current conditions?
- How often do similar extremes occur?
- How far can conditions move away from the average?
That context matters when decisions depend not on typical weather, but on thresholds and extremes.
From history to operational insight
OpenWeather’s Historical Weather Collection provides 47+ years of historical weather data, dating back to 1 January 1979, for locations worldwide.
For energy and utilities, that can mean analysing how wind, solar radiation and temperature have varied over time and how assets might perform under less favourable conditions.
For transport and infrastructure, historical heat, frost, precipitation and wind can show how often roads, railways or other assets have been exposed to potentially disruptive weather.
For cities and industrial operators, location-specific historical data can support site-level risk analysis rather than relying only on regional averages.
The value is not simply in knowing what happened, but in understanding how unusual it was and what similar conditions could mean operationally.
Combining history with forecasts
Historical data becomes even more useful when paired with forecasting. A forecast tells you what may happen next. Historical data adds context: how unusual is it, and what happened when similar conditions occurred before?
A utility can compare an expected cold spell with previous periods of similar temperature. A renewable energy operator can benchmark a forecast low-wind period against historical wind conditions. A transport authority can see how often a forecast rainfall or temperature threshold has previously been reached. This helps turn weather forecasts into more meaningful operational information.
Putting 47+ years of weather history to work
OpenWeather historical data can support:
- historical baselines;
- comparison of current conditions with previous years;
- analysis of past extremes;
- operational event review;
- stress-testing of planning assumptions;
- risk modelling;
- historical context for forecasts.
The IPCC debate is about turning decades of evidence into decisions at a global level. For businesses, the scale is different, but the principle is the same: the longer the record, the stronger the context for the decisions being made today.