Climatic Information
ASHRAE Technical Committee 4.2

Scope of TC 4.2

TC 4.2 identifies, researches, analyzes, and disseminates climatic data for design of sustainable built environments.


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 9,237 locations in the United States, Canada, and around the world. This is an increase of 1,119 stations from the 2017 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 9,237 stations are contained in the pdf files that accompany the volume.
The map of all 9,237 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. is an online application, also called the Weather Data Viewer (WDView), which provides access to the processed climatic data and the underlying frequency data used to develop the tables of climatic design conditions found in Chater 14, for further analysis and visualization.

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 projects that are scheduled to start in 2022:

1874-RP – Addition of Roof Top Temperature Information to the Climatic Design Conditions chapter of the ASHRAE Handbook
This research projects aims at studying the impact of a building itself on its own immediate environment, as when a hot roof elevates the temperature of the intake air of a Rooftop Unit (RTU). The completion of this project will give more correct climate design information for RTUs and wall-mounted ACUs (via a simple algorithm or look-up table) to engineers and application designers, allowing systems and components to be designed and selected appropriately for the climate conditions they will actually be exposed to.

1900-RP – Using simulated weather data with sparse measured data to produce hourly weather files and calculate design conditions
The purpose of this research project is to combine the output of numerical weather models (reanalysis and numerical weather prediction) with sparse measured data to produce hourly time-series and design climatic data. The ultimate goal is potentially to allow the calculation of climatic design conditions or the creation of weather files for building performance modelling, for regions of the world with very limited climate data. The underlying assumption is that climate reanalysis models correctly represent the overall physics and dynamics of the atmosphere, but can benefit significantly from tuning against measured data, even in cases where only limited data is available. 

1923-RP – Prepare climatic design conditions for the 2025 ASHRAE Handbook – Fundamentals and ASHRAE Standard 169
This research project will recalculate the tables of climatic conditions in Chapter 14 of the ASHRAE Handbook – Fundamentals,
using for most stations hourly weather stations data for the period 1999-2023 (25 years) from the National Oceanic and Atmosphere Administration (NOAA) and Environment Canada (EC). It will also update the same information in Standard 169, Climatic Data for Building Design Standards.


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
Please see the SSPC 169 web page for more information.

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.