What is a future weather file?

A future weather file, also known as a predictive weather file, is an innovative type of weather file that portrays a location's anticipated annual weather stream in 10, 25, 50, 80, and 100 years into the future. Based on projections derived from numerous global climate models for various scenarios of greenhouse gas emissions, future weather files can be utilized in building energy modeling to get insights into future energy requirements. These studies can be applied in many ways, including risk-based resiliency planning of buildings and infrastructure, and minimization of life-cycle costs.

Why are they important?

Predictions published by the Intergovernmental Panel on Climate Change (IPCC) indicate an increase in global average surface temperature which ranges from 1.1–2.9 °C to 2.4–6.4 °C by the end of the 21st century. It is crucial to understand the impact of climate change on buildings' energy consumption and address it by implementing proper energy conservation methods. Building simulation techniques combined with projected/future weather data are frequently used to examine the influence of climate change on the built environment.

What is a weather file and what are the common weather files format?

A weather file is a text file containing daily observations of temperature, humidity, wind, solar radiation, and precipitation at various elevations that profiles a particular climate zone's annual weather stream. Weather files come in various formats, however, cove.tool only uses the EPW format (EnergyPlus Weather) which has been derived from a wide range of sources including TMY2, TMY3, IWEC, and RMY.

When it comes to weather file, ones should pay attention to the accuracy of data and their age. Climate is constantly changing in all the regions across the world and most updated weather files which better resemble the climatic condition result in more accurate EUI estimation. For instance, when using TMY3 files as a starting point, obtaining a set of files for 2020 for RCP 8.5 is recommended to provide data for current climate conditions, since the historical weather data used to construct those files was recorded from 1976-2005 for most TMY3 files and is now approximately 25 years out of date.


Here are resources that can be used for future projection of weather data:

  • Meteonorm is a combination of a climate database and a weather generator. It delivers typical meteorological years for any place. The current version 8 includes historical and future climate data as well as simplified access to extended current time series.
    Time Frame: 2020 - 2100

  • WeatherShift is an interactive online tool that is publicly accessible. It makes use of data projections from several global climate models used in IPCC AR5 to construct predicted distributions of weather parameters for a typical year in future time periods at a geographical location specified by the user.
    Time Frame: 2020 - 2100

  • CCWorldWeatherGen allows you to generate climate change weather files for world-wide locations ready for use in building performance simulation programs. The tool is Microsoft® Excel based and transforms ‘present-day’ EPW weather files into climate change EPW or TMY2 weather files which are compatible with the majority of building performance simulation programs.
    Time Frame: 2020 - 2100

Interactive maps:

Alternatively, interactive maps can be used to find the predicted future weather of a particular place with respect to the current weather file of another location:

  • The Crowther Lab has explored how global heating will affect 520 cities around the world and matched those predictions with cities that experience those temperatures today. The result is a simple to understand example of the likely results of global heating. Click on your city on the Future Cities interactive map and you can find out which city's climate your city will resemble in 2050 as a result of climate change.

    When you select a city on the Future Cities interactive map you can also view details on the expected annual increase in temperature and the expected increase in temperature in the warmest & coldest months. The sharpest rise predicted by Crowther Lab will be in St. Louis. It is expected to see an increase in annual temperatures of 3.6 degrees centigrade. It will therefore experience a climate similar to that of Dallas today.

  • 23 Degrees has also released a clever interactive map which allows you to find your climate analog for the year 2080. Using this climate change model, Frankfurt in Germany will be as hot as Malawi today and living in Berlin will be like living in Lesotho in southern Africa.

    If you enter your location or click on your location on the map you can view the town or city in the world which has a climate now which is similar to the climate you can expect in your location in the year 2080. The map uses two different climate models. This allows you to find your climate twin for a global heating scenario of 4.2 degrees or 1.8 degrees.


How cove.tool help you to predict future energy requirements?

Using cove.tool you can now upload custom weather files to the loadmodeling.tool and in near future to the project info page and plan for a future-proof building based on energy predictions in the sight of climate change. Take the steps below to upload a weather file to cove.tool:

Step 1: Download/Generate a custom future weather file.

Step 2: Upload this custom weather file to cove.tool

Once you have uploaded your weather file, you can turn back to your Baseline Energy page to find the energy results for the custom weather file you just uploaded!

Happy Modeling!

Related Links:

  1. Custom Weather File Upload

  2. What is a weather file and which ones do we reference

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