NOAA releases new Typical Meteorological Year for planning and construction

NCEI dataset as a new reference

The National Centers for Environmental Information (NCEI) of NOAA published an updated Typical Meteorological Year (TMY) on 13 April 2026. The dataset consolidates hourly, site‑typical weather values and serves as a standard basis for simulations and verifications in architecture, engineering and energy planning.

What is the Typical Meteorological Year?

A TMY is a synthetic year derived from long‑term measurements. Characteristic months are combined so that long‑term averages and seasonal patterns are represented in a representative way. TMY datasets enable comparable calculations of energy demand, heating and cooling loads, solar yields and the sizing of technical systems.

Why the release matters

Updated, quality‑checked reference data improve the comparability of projects and the reliability of technical calculations. Common building and energy simulation programs use TMY by default; the new version therefore flows directly into design and verification processes.

Application areas in projects and cities

– Architecture: Assessment of summer and winter thermal protection, effectiveness of shading and potential for natural ventilation. – Building services engineering: Sizing of heating, ventilation and air‑conditioning systems and estimation of peak loads. – Energy systems: Simulation of typical annual yields for photovoltaic systems and heat pumps. – Urban and district planning: Consistent climate basis for energy scenarios, peak load estimates and green infrastructure. – Financing and operation: Assessment of energy efficiency and operating costs as part of risk management.

Limits of the TMY method

TMY represents "typical" conditions — not the extreme events that place particular stress on infrastructure and buildings. Heat and cold waves, heavy precipitation and long‑term trends can only be represented to a limited extent with a single typical year. For tasks with high resilience requirements, complementary analyses are necessary, such as extreme‑event statistics, climate projections and scenario‑based stress tests.

Integration into climate‑robust planning

A staged approach has proven effective: use TMY as a baseline scenario for normal operation and comparability; additionally run simulations with shifted means and intensified extremes to estimate climate change impacts. Considering both typical conditions and stressful scenarios together increases operational security and reduces follow‑up costs.

Data access and quality assurance

Open, transparently documented datasets reduce information gaps between large and small actors. Quality control, complete metadata and clear guidance on suitability and limitations support appropriate use and the selection of complementary analyses.

Impacts on standards and practice

Updated climate baselines can influence technical rules and standards — for example for energy assessment, ventilation or system sizing. Authorities, standards bodies and planners should review data‑driven updates to avoid mis‑sizing. Unified data bases are particularly important for tenders and funding programmes.

What planners should consider now

– Use TMY as the baseline scenario for standard verifications. – Complement with extreme scenarios and sensitivity analyses. – Include regional climate projections for trends and risks. – Document data bases and assumptions transparently. – Collaborate interdisciplinarily (architecture, MEP, climate science, operations).

The new TMY release is an important building block for climate‑adapted planning. Critical for resilient outcomes is the combined consideration of typical conditions and stressful exceptional situations.