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Future weather file generators: morphing EPW files for climate change

A future weather file shifts today's hourly weather to match a climate projection, so you can test overheating, comfort and energy use over a building's life. These tools make one, from free research software to paid services.

Last checked18 September 2026

At a glance

ToolTypePriceBest for
Future Weather GeneratorDesktop app (Java, cross-platform)Free (non-commercial CC BY-NC-SA 4.0 licence)Free, research-grade future EPW files with a choice of global CMIP6 or regional CORDEX climate data.
MeteonormWeb app and APIFrom CHF 320/year (Basic); Pro CHF 980/year; Expert CHF 4,200/year; one-off datasets on requestFuture typical years generated directly for any location, without supplying your own EPW.
Future WeatherWeb app and API5 free credits on sign-up; subscriptions from US$149/month (8 credits); US$50 for a single credit; 1 credit per job (one future EPW, with optional DDY and STAT files)Quick future EPW, DDY and STAT files through a web interface or API, with nothing to install.
C4BWeb appFuture climate in projects on paid plans from €59/month (cancellation takes effect after 12 billing cycles) or €599/year; future EPW downloads on the Technical and Enterprise plans (custom quote)Seeing what a site's future climate means for comfort, wind, PV and energy use, starting from an address.
WeatherShiftWeb appFuture EPW (fTMY) files: US$285 for the first scenario, US$200 for each additional scenarioFuture EPW and design-day files for a location, with percentiles to test a range of outcomes.
DesignBuilder Climate AnalyticsWeb app€895/year, including 150 download creditsEnergy modellers who want future projections applied to design-year weather files from a large station library.
EPW InsightsWeb app, open source (AGPL-3.0)FreeA free first look, in the browser, at how an EPW's climate shifts under CMIP6 scenarios.
CCWorldWeatherGenMicrosoft Excel toolFreeReproducing studies that used the long-established HadCM3-based morphing workflow.
epwshiftrR package, open source (MIT)FreeResearchers who want to script their own CMIP6 future EPW files in R.

How to choose

Almost every tool here uses morphing: it takes a present-day EPW and shifts, stretches or scales its hourly values by the monthly changes a climate model projects for a future period. The result can only be as good as the starting file, so begin with a recent, representative typical year for the site.

Then check the climate data. Most current tools use CMIP6 models, the generation behind the IPCC's Sixth Assessment Report, with SSP scenarios; older tools and regional CORDEX datasets use CMIP5 (RCP scenarios) or earlier model generations. Check how many models are combined, too: an ensemble or multi-model median is less exposed to one model's quirks than a single model, and some tools let you pick a percentile to test a hotter outcome.

Match the time horizon to the building. Many tools offer fixed 30-year periods centred on about 2050 and 2080; others let you choose any year. A building completed in 2030 with a 60-year life needs mid-century and later projections, not only the next decade.

Finally, check what you get: an EPW you can use in any simulation tool, extra files such as design days, or only charts. Research tools are free but need some setup; commercial services charge per file or by subscription.

Future Weather Generator

CURA Lab, University of Coimbra · Desktop app (Java, cross-platform) · Free (non-commercial CC BY-NC-SA 4.0 licence)

Free, research-grade future EPW files with a choice of global CMIP6 or regional CORDEX climate data.

  • The global distribution uses CMIP6 models under SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5, for 2036–2065 (labelled 2050) and 2066–2095 (labelled 2080).
  • Regional distributions use CORDEX simulations with RCP scenarios, down to a 0.11° grid (about 12.5 km) for Europe.
  • Single models or user-selected multi-model ensembles, with graphical and command-line interfaces.

Good to know

  • Runs as a Java application on your computer and needs a baseline EPW; it offers 30-year periods rather than any single year.

Visit Future Weather Generator

Meteonorm

Meteotest AG · Web app and API · From CHF 320/year (Basic); Pro CHF 980/year; Expert CHF 4,200/year; one-off datasets on request

Future typical years generated directly for any location, without supplying your own EPW.

  • Future climate scenarios under SSP1-2.6, SSP2-4.5 and SSP3-7.0.
  • Starts from its own data (10,000 stations, 5 satellites and reanalysis), so no baseline file is needed.
  • Exports EPW and many other simulation formats.

Visit Meteonorm

Future Weather

Radbridge Incorporated · Web app and API · 5 free credits on sign-up; subscriptions from US$149/month (8 credits); US$50 for a single credit; 1 credit per job (one future EPW, with optional DDY and STAT files)

Quick future EPW, DDY and STAT files through a web interface or API, with nothing to install.

  • Morphing based on the University of Coimbra's Future Weather Generator research, with its own platform additions.
  • 23 CMIP6 global climate models, used as a full ensemble or a combination you choose, with flexible time periods.
  • Outputs EPW with optional DDY and STAT files; you upload the baseline EPW.

Visit Future Weather

C4B

We make C4B

Embrace Ideas · Web app · Future climate in projects on paid plans from €59/month (cancellation takes effect after 12 billing cycles) or €599/year; future EPW downloads on the Technical and Enterprise plans (custom quote)

Seeing what a site's future climate means for comfort, wind, PV and energy use, starting from an address.

  • Morphs the site's weather file to any year from 2025 to 2100 under SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 or SSP5-8.5.
  • Uses the World Bank Climate Change Knowledge Portal's CMIP6 multi-model median for temperature, humidity and solar radiation, applied mainly with the Eames et al. (2024) morphing method.
  • Prepares four SSP scenarios automatically for the building's default mid-life year, 27 years ahead, and overlays present and future on temperature, UTCI, the wind rose, cloud cover, solar radiation, PV potential and the energy balance.

Good to know

  • Downloading future EPW files is only available on the Technical and Enterprise plans; on Essential and Teams the future files are used inside C4B's analyses.

WeatherShift

Arup and Argos Analytics · Web app · Future EPW (fTMY) files: US$285 for the first scenario, US$200 for each additional scenario

Future EPW and design-day files for a location, with percentiles to test a range of outcomes.

  • WeatherShift Heat produces future EPW (fTMY) and ASHRAE design-day (fDD) files, and states that it uses CMIP6 global climate modelling data.
  • A free viewer shows pre-analysed monthly changes under RCP 4.5 and RCP 8.5, at warming percentiles from 10% to 95%.
  • WeatherShift Rain separately sells future rainfall intensity-duration-frequency data.

Good to know

  • Some locations are preloaded from US Department of Energy EPW files; for others you upload an EPW or design-day file as the baseline.

Visit WeatherShift

DesignBuilder Climate Analytics

DesignBuilder Software Ltd · Web app · €895/year, including 150 download credits

Energy modellers who want future projections applied to design-year weather files from a large station library.

  • Applies CMIP6 SSP projections, and the earlier IPCC SRES scenarios, to its Design Year data.
  • Future files download in EPW format.
  • Part of a weather data service covering over 43,000 stations.

Visit DesignBuilder Climate Analytics

EPW Insights

Ehsan Rostami · Web app, open source (AGPL-3.0) · Free

A free first look, in the browser, at how an EPW's climate shifts under CMIP6 scenarios.

  • Projections for 2030, 2050 and 2080 under SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5, using CMIP6 morphing.
  • Side-by-side comparison of present and future files or scenarios.
  • Runs locally in the browser, with nothing uploaded.

Good to know

  • Morphed data exports as CSV; a morphed EPW download is not among its documented features.

Visit EPW Insights

CCWorldWeatherGen

University of Southampton · Microsoft Excel tool · Free

Reproducing studies that used the long-established HadCM3-based morphing workflow.

  • Morphs present-day EPW files into climate-change EPW or TMY2 files with the Belcher, Hacker and Powell morphing method.
  • Uses IPCC Third Assessment Report data from the HadCM3 A2 experiment ensemble.

Good to know

  • Distributed without the baseline weather files or climate scenario data, which you download separately.
  • Its page states that it does not currently work with Excel 2013 and recommends Excel 2003, 2007 or 2010. Latest manual: version 1.9, September 2022.

Visit CCWorldWeatherGen

epwshiftr

Hongyuan Jia and Adrian Chong (ideas-lab-nus) · R package, open source (MIT) · Free

Researchers who want to script their own CMIP6 future EPW files in R.

  • Requests CMIP6 projection data, extracts site-level climate variables, morphs a baseline EPW and writes future EPW files.
  • Released under the MIT licence.

Good to know

  • Latest tagged release: v0.1.4 (March 2024). The CRAN page lists the package as removed from CRAN; the source is on GitHub.

Visit epwshiftr

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Frequently asked questions

What is a future weather file?

An hourly weather file, usually in EPW format, adjusted to represent the climate projected for a future period under a given emissions scenario. It lets you run the same comfort or energy simulation for today's climate and for, say, the middle of the century.

What is weather file morphing?

Morphing shifts, stretches or scales each hourly value of a present-day weather file by the monthly changes a climate model projects, for example adding the projected rise in mean temperature. The file keeps a realistic hourly pattern but reflects the future climate. The method used by most tools goes back to Belcher, Hacker and Powell (2005).

Which SSP scenario should I use?

There is no single right answer. SSP2-4.5 is often used as a middle-of-the-road case and SSP5-8.5 as a high-emissions stress test. Testing more than one scenario, and more than one period, shows how sensitive the design is to the uncertainty.

Are there free future weather file generators?

Yes. Future Weather Generator from the University of Coimbra (under a non-commercial CC BY-NC-SA 4.0 licence), CCWorldWeatherGen from the University of Southampton and the epwshiftr R package are free. Climate.OneBuilding.Org also publishes ready-made future files for some countries, including Canada and Brazil.

Can I download future EPW files from C4B?

Yes, on the Technical and Enterprise plans. Projects on the Essential and Teams plans can generate future scenarios and see them overlaid on C4B's analyses, but cannot download the files.

Sources

We make C4B. Information about the other tools comes from their official websites and documentation, checked on 18 September 2026. Products and prices change, so check each vendor's site for the latest details. All product names belong to their respective owners.

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