Climatic Information
ASHRAE Technical Committee 4.2

Scope of TC 4.2

TC 4.2 is concerned with identification, analysis and tabulation of climatic data for use in analysis and design of heating, refrigeration, ventilation and air-conditioning systems. Promotion of effective use of weather information in these applications is also included.


The ASHRAE Handbook is published in a series of four volumes, one of which is revised each year, ensuring that no volume is older than four years.

The Handbook can be purchased at the ASHRAE Bookstore by clicking on this link.

This TC is responsible for the following chapter in the Fundamentals Volume:

Chapter 14 - Climatic Design Information
This chapter and the data in the accompanying files provide the climatic design information for 8,118 locations in the United States, Canada, and around the world. This is an increase of 1,675 stations from the 2013 ASHRAE Handbook— Fundamentals. As in the previous edition, the large number of stations made printing the whole tables impractical. Consequently, the complete table of design conditions for only Atlanta, GA, appears in this printed chapter to illustrate the table format. However, a subset of the table elements most often used is presented in the Appendix at the end of this chapter for selected stations representing major urban centers in the United States, Canada, and around the world. The complete data tables for all 8,118 stations are contained in the pdf files that accompany the volume.
The map of all 8,118 sites for which climatic design information is available is available through the following link:

The ASHRAE FUNDAMENTALS HANDBOOK may be purchased from the on-line bookstore by clicking on the highlighted text.

Comment on the Handbook: ASHRAE welcomes your comments on the Handbook or a specific Handbook chapter.  To submit a comment about any aspect or part of the Handbook series, you can use the Handbook Comment Form.

Review a Handbook Chapter: To provide your feedback about a specific Handbook chapter, you can answer the brief survey questions on the Handbook Chapter Review Form.


Technical committees develop and sponsor technical sessions at the winter and annual conferences. Information about their future technical program is discussed at each TC meeting and at the TC’s Program Subcommittee meeting.

ASHRAE publishes papers and transactions from presentations at its conference events. In addition, ASHRAE records most of the seminar sessions from its conferences on DVD. These DVDs are ideal for use at chapter meetings, in university courses, or company lunch and learns. Products available from the most recent conference may be found here.


Technical Committees are responsible for identifying research topics, proposing research projects, selecting bidders, and monitoring research projects funded by ASHRAE. Information about their specific research program is discussed at each TC meeting and at the TC’s Research Subcommittee meeting.

This TC has the following active research projects:


Climate reanalysis refers to the use of archival data from large Climate Forecasting Models (CFM) that assimilate historical data from weather stations to forecast the weather conditions for the upcoming days up to a week. In reanalysis mode, the CFM is used not to forecast, but to develop a complete map of weather conditions throughout the spatial domain and time period covered by the CFM.
There are now several reanalysis data sets in the public domain, including two that cover the entire world: (1) the Climate Forecast System Reanalysis (CFSR) maintained by the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) National Centers for Environmental Prediction, and (2) the Modern-Era Retrospective Analysis for Research and Applications (MERRA) which was undertaken by the National Aeronautics and Space Administration's (NASA) Global Modeling and Assimilation Office.
The main purpose of this research project is to evaluate whether MFSR and MERRA can be used to supplement ground stations for building energy modeling and for the calculation of climatic design conditions. The five main objectives are: (1) carry out a technical assessment of the methodologies and procedures used in both platforms to the level of detail necessary to understand how they work, including how gridded results are downscaled to produce weather data at specific locations, (2) demonstrate and document ability to extract and post-process reanalysis data into hourly time-series data for selected locations, (3) statistically analyze the accuracy of reanalysis data compared to actual measured data, (4) assess ASHRAE use cases involving design conditions and derived hourly weather files' impact on building energy use, and (5) develop guidelines for the appropriate use of reanalysis data in ASHRAE applications.


ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry. ASHRAE publishes the following three types of voluntary consensus standards: Method of Measurement or Test (MOT), Standard Design and Standard Practice. ASHRAE does not write rating standards unless a suitable rating standard will not otherwise be available. ASHRAE is accredited by the American National Standards Institute (ANSI) and follows ANSI's requirements for due process and standards development. Standards may be purchased at the ASHRAE Bookstore.

This TC is cognizant for the following standard:

ANSI/ASHRAE Standard 169: Climatic Data for Building Design Standards

Other Activities

TIP: If MTG involvement add here otherwise leave blank.


ASHRAE Technical FAQs are provided as a service to ASHRAE members, users of ASHRAE publications, and the general public. While every effort has been made to ensure their accuracy and reliability, they are advisory and provided for informational purposes only, and in many cases represent only one person’s view. They are not intended and should not be relied on as an official statement of ASHRAE. Technical questions not addressed may be submitted to the ASHRAE Technical Services department at

This TC is responsible for the following frequently asked questions:

Where can I get design weather data for my area? (41)
Where can I get hourly, daily, and monthly weather data for my area? (42)
Where can I get historic weather data for a particular time period to show that it was unusually hot or cold? (43)

Additional FAQs related to climatic information can be found on this link.