ASHRAE 169 Climate Zone Tool
Beta Version 1.0 I 28/11/2025
What is this tool?
The ASHRAE Climate Zone Filter is a browser-based lookup tool for ASHRAE Standard 169-2021 climate data. It indexes 4,429 weather stations worldwide and maps them to climate zones, which saves you from digging through the standard's tables every time you need to verify a zone assignment.
This is useful if you're doing energy modeling, code compliance work, or anything else where you need to reference ASHRAE 169 with any regularity. The tool runs entirely client-side, so once the page loads, filtering is instantaneous.
Download the tool here: ASHRAE 169 Climate Zone Tool V 1.0
Global Coverage
The tool includes complete worldwide coverage:
Americas: 2,150 stations (United States, Canada, Mexico, Brazil, Argentina, Chile, Peru, Colombia, Ecuador, Central America)
Europe/Russia: 957 stations
Asia/Middle East: 796 stations
Oceania: 308 stations (Australia, New Zealand, Pacific Islands)
Africa: 126 stations
What It Actually Does
The tool provides two main functions:
Station lookup. You can filter by region/country, climate zone, or search by station name or WMO number. Results update in real time as you type or adjust filters.
Climate zone identification. Each station displays its assigned climate zone in the familiar format: a number (0-8, representing thermal load) and a letter (A/B/C, representing moisture regime). So "3A" means warm and humid, "5B" means cool and dry, and so on.
The interface is straightforward. You get a table of stations with sortable columns, filters at the top, and a map view if you want to see things geographically. Nothing fancy, which is appropriate for a lookup tool.
How Climate Zones Actually Work
ASHRAE 169 assigns climate zones based on heating degree days and precipitation. The zones exist to inform building energy code requirements, which is why they show up in ASHRAE 90.1 and the IECC.
The number indicates thermal classification:
0-2: Hot climates (minimal heating loads)
3-4: Mixed climates (moderate heating and cooling)
5-6: Cold climates (significant heating loads)
7-8: Very cold to subarctic (dominated by heating)
The letter indicates moisture:
A: Humid (more than 20 inches of annual precipitation)
B: Dry (less than 20 inches)
C: Marine (cool, wet summers; mild winters)
So Dallas is 3A because it's warm with humid summers. Denver is 5B because it's cool and dry. Seattle is 4C because it's mild and marine. The system works well enough that most people in the industry know their local zone without looking it up.
Interface and Filtering
The tool has two views: table and map.
Table view is the default. Five columns: region/country, station name, WMO number, coordinates, and climate zone. You can sort by clicking any column header, which is useful when you're trying to group results by zone or location.
Map view plots all 4,429 stations on an OpenStreetMap base layer. Markers are color-coded by climate zone (red for hot, blue for cool, gray for cold). Click a marker and you get a popup with station details. The map starts zoomed out to show the entire world, then auto-zooms to your filtered results. It's visually helpful if you're trying to understand regional patterns or if you're presenting to someone who doesn't want to stare at a table.
Filtering works the way you'd expect. Select a region/country, and results narrow to stations in that location. Select a climate zone and the results narrow further. Type in the search box and the table filters in real time. You can combine filters, so you could show "all Zone 3A stations in Brazil" or "stations in Europe with Zone 5B."
The search box is forgiving. It matches station names and WMO numbers, and it's case-insensitive. So if you search "Tokyo" you get Tokyo Haneda and Tokyo Narita. If you search "722190" you get Atlanta Hartsfield-Jackson by WMO number.
One thing the tool doesn't do: export. You can't download a CSV of filtered results. If you need a dataset, you either copy from the table manually or contact Better Building support.
Use Cases
Single building projects. You need to confirm the climate zone for an office building in Sydney. Filter by region (Oceania), search "Sydney," and you immediately see the zone assignment. Takes about thirty seconds.
Multi-location portfolios. You're managing a retail chain with stores in ten countries. Open the tool, filter by region for each location, note the climate zones. You can use map view to see them all at once geographically, which is helpful for understanding regional patterns.
Code compliance. You're documenting climate zone assignments for IECC or ASHRAE 90.1 compliance. Look up the station near your project location, screenshot the table showing the zone, and reference ASHRAE Standard 169-2021 directly. The WMO number and coordinates provide traceable documentation if anyone questions the assignment.
Design charrettes. Someone asks, mid-meeting, "What zone is our Tokyo project?" You search "Tokyo," see the zone, and answer in thirty seconds. Someone else asks how it compares to the Singapore location. You search "Singapore," see the zone. Real-time answers with credible data.
International projects. Now you can quickly look up climate zones for projects anywhere in the world. Compare climate zones across different continents, understand regional patterns, and make informed decisions for global building portfolios.
What It Doesn't Do
The tool doesn't update weather data. It links to a database compiled from ASHRAE 169-2021. If climate conditions shift or ASHRAE publishes a revised standard, the tool will need to be updated. Better Building has committed to keeping it current, but for now, it's a snapshot of 2021 data.
The tool doesn't help with climate zones that fall outside ASHRAE 169. If you're working with DOE climate zones, Köppen-Geiger classifications, or any other system, this won't help.
And as mentioned, there's no data export yet. That's coming in a future version.
Technical Notes
The tool is a single HTML5 file. No server-side processing, no database queries, no API calls. The entire station dataset is embedded in the page as JSON, which is why filtering is instant once the page loads.
The map uses Leaflet.js with OpenStreetMap tiles, so you do need an internet connection for the map to render. The table view works offline once the page is cached.
Browser requirements are minimal. Any modern browser with JavaScript enabled will work. The tool is responsive, so it functions on mobile, though filtering and map interaction are more practical on a desktop.
Data Quality Improvements (v2.0)
This version includes significant data quality enhancements:
Fixed 1,069 state field errors in the US dataset where stations were assigned to incorrect states
Improved coordinate parsing to properly handle international data with en-dash negative signs
Geographic validation using coordinate-based region detection to ensure accurate country/region assignments
Cleaned station names removing control characters and formatting issues that caused JavaScript errors
Quick Start Guide
Finding Your Climate Zone (3 Steps)
Step 1: Locate Your Station
Choose your preferred method:
Using Search (fastest, ~10 seconds):
Type city name or station name in the "Search" field
Results filter instantly as you type
Locate your station in the table
Using Filters (specific, ~30 seconds):
Select your region/country from dropdown
Select your climate zone (optional)
View filtered results in table
Using Map (visual, ~60 seconds):
Click "Map View" tab
Navigate to your location on the map
Click color-coded markers to see station details
Step 2: Identify Climate Zone
View in table:
Climate zone appears in "Climate Zone" column
Color-coded badge indicates zone type
Format: Number (0-8) + Letter (A/B/C)
Example zones:
3A: Warm/Humid (Atlanta, Birmingham, São Paulo)
4A: Mixed/Humid (New York, Boston, Paris)
5B: Cool/Dry (Denver, Madrid, Tehran)
2A: Hot/Humid (Houston, Singapore, Mumbai)
Step 3: Document for Your Project
Screenshot the table showing your zone
Note the WMO number and coordinates
Reference ASHRAE Standard 169-2021
Keyboard Shortcuts
Tab: Navigate between filters
Enter: Apply filters (when in dropdown/search)
Ctrl+F: Browser find (search in current results)
FAQ
Q: Why doesn't my city appear in the list? A: The tool shows weather stations from ASHRAE Standard 169-2021, not all cities. Use the nearest weather station, typically located at major airports or in capital cities.
Q: Can I use a station from a different country? A: For international projects, use the nearest station with similar climate characteristics. For US projects, always use a station from your project's county. Climate zone accuracy decreases with distance from the reference station.
Q: What if two stations in the same city show different zones? A: This can occur in large metropolitan areas or when a city spans different climate regions. Use the station closest to your project location, or the one at the major airport serving that city.
Q: How accurate are the coordinates? A: Coordinates are accurate to ±111 meters (3 decimal places). This is sufficient for climate zone identification.
Q: Can I download the complete station list? A: Export functionality is coming in a future version. Currently, you can filter results and copy from the table, or contact support for a complete CSV file.
Q: Is this tool updated when ASHRAE releases new standards? A: Yes. The tool will be updated to match the latest ASHRAE Standard 169 revisions. Current version is based on ASHRAE 169-2021.
Q: Why do some stations show no climate zone? A: Some stations lack climate zone assignments. This can occur for marine stations, remote locations, or areas not covered by ASHRAE's climate classification system. Use the nearest station with assigned zone data.
Q: How were the international regions determined? A: Regions are determined using geographic coordinate ranges. The system classifies stations into regions (Americas, Europe, Russia, Asia, Middle East, Africa, Oceania) based on latitude and longitude. This ensures consistent, reproducible assignments.
Q: Can I filter by specific countries within a region? A: The current version filters by major regions and countries. More granular country-level filtering will be added in a future update.
Regional Coverage Details
Americas (2,150 stations)
United States: 1,663 stations
Canada: 247 stations
Central America: 79 stations
Brazil: 61 stations
Argentina: 28 stations
Mexico: 25 stations
Ecuador: 16 stations
Peru: 11 stations
Chile: 1 station
Other South America: 19 stations
Europe/Russia (957 stations)
Europe: 629 stations
Russia: 328 stations
Asia/Middle East (796 stations)
Asia: 664 stations
Middle East: 132 stations
Oceania (308 stations)
Including Australia, New Zealand, and Pacific Islands
Africa (126 stations)
Coverage across major cities and regions
Compared to Alternatives
Before this tool existed, you looked up climate zones by manually referencing ASHRAE Standard 169-2021 tables, which list locations and their assigned zones. This works, but it's tedious if you're doing it repeatedly, and the tables are long enough that you can lose your place.
For international projects, finding climate data often required consulting multiple sources or purchasing expensive climate databases.
The ASHRAE Climate Zone Filter is faster and more convenient. For anyone doing regular energy modeling or code compliance work with international projects, it's a significant time saver.
Practical Recommendations
If you do building performance work with any frequency, bookmark this tool. You'll use it.
If you're presenting climate data to a client or reviewer, use the map view. Color-coded markers are easier to understand than a table, and the visual reinforces that you're using a systematic, standard-based approach.
If you're documenting for code compliance, use the table view. Screenshot the filtered results, note the WMO number and coordinates, and include a reference to ASHRAE 169-2021. This provides traceability if the building department has questions.
For international projects, remember that climate zones may have different code implications in different countries. Always verify local building code requirements in addition to the ASHRAE climate classification.
And if you're working in a location without a nearby weather station, don't improvise. Cross-reference ASHRAE 169-2021 directly or consult with a local climate expert to confirm the appropriate zone assignment.
Version History
Version 2.0 (Global Edition)
Expanded from 2,113 US-only stations to 4,429 global stations
Added international coverage: Europe, Asia, Middle East, Africa, Oceania, South America
Fixed 1,069 state field errors in US data (50.6% of dataset)
Improved coordinate parsing for international en-dash format
Removed state/county fields from map popups for cleaner international display
Updated map default view to show entire world
Enhanced region detection algorithm for accurate geographic classification
Version 1.0 (US Edition)
Initial release with 2,113 US weather stations
State and county filtering
Climate zone assignments
Map and table views
Real-time search and filtering
Support & Resources
Better Building Resources:
Documentation: [email protected]
Support Ticket System available
User guides and tutorials
ASHRAE Resources:
ASHRAE Standard 169-2021
Climate Design Conditions
Technical Resources
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