ASHRAE-Based Climatic Design Conditions (50 US States & Canada)
Reference climatic design conditions (99% and 99.6% winter heating dry-bulb, 0.4% and 1.0% summer cooling dry-bulb, and coincident wet-bulb temperatures) across all 50 US states, the District of Columbia, and Canadian metropolitan weather stations. Based on published meteorological design information from the ASHRAE Handbook of Fundamentals (Climatic Design Information) and ACCA Manual J (8th Edition) reference tables.
U.S. Stations: Referenced from published ASHRAE Handbook of Fundamentals station data and ACCA Manual J (8th Ed) Table 1A.
Canadian Stations: Referenced from Environment Canada and ASHRAE international climatic design summaries.
Dataset Version: 2026.1 • Last Updated: 2026-10-01
| Station / Location | IECC Zone | Winter 99% DB | Winter 99.6% DB | Summer 0.4% DB | Coincident WB | Elevation | Load Sizing Inputs |
|---|---|---|---|---|---|---|---|
| Birmingham, ALAlabama | 3A | 22°F | 18°F | 93°F | 76°F | 644 ft | |
| Mobile, ALAlabama | 2A | 29°F | 25°F | 93°F | 78°F | 219 ft | |
| Huntsville, ALAlabama | 3A | 18°F | 14°F | 93°F | 76°F | 629 ft | |
| Anchorage, AKAlaska | 7 | -10°F | -16°F | 71°F | 58°F | 144 ft | |
| Fairbanks, AKAlaska | 8 | -42°F | -48°F | 82°F | 62°F | 434 ft | |
| Phoenix, AZArizona | 2B | 41°F | 38°F | 109°F | 71°F | 1,107 ft | |
| Tucson, AZArizona | 2B | 34°F | 31°F | 103°F | 68°F | 2,584 ft | |
| Flagstaff, AZArizona | 5B | 2°F | -4°F | 86°F | 57°F | 7,014 ft | |
| Little Rock, ARArkansas | 3A | 21°F | 16°F | 96°F | 77°F | 260 ft | |
| Los Angeles (LAX), CACalifornia | 3B | 46°F | 43°F | 80°F | 66°F | 125 ft | |
| San Francisco, CACalifornia | 3C | 41°F | 38°F | 77°F | 61°F | 52 ft | |
| San Diego, CACalifornia | 3B | 46°F | 43°F | 81°F | 68°F | 29 ft | |
| Sacramento, CACalifornia | 3B | 33°F | 30°F | 98°F | 69°F | 26 ft | |
| Fresno, CACalifornia | 3B | 32°F | 29°F | 101°F | 70°F | 336 ft | |
| Denver, COColorado | 5B | 2°F | -4°F | 93°F | 61°F | 5,431 ft | |
| Colorado Springs, COColorado | 5B | 1°F | -5°F | 89°F | 59°F | 6,172 ft | |
| Hartford, CTConnecticut | 5A | 5°F | 0°F | 90°F | 73°F | 180 ft | |
| Wilmington, DEDelaware | 4A | 14°F | 9°F | 91°F | 75°F | 80 ft | |
| Washington (Reagan), DCDistrict of Columbia | 4A | 18°F | 14°F | 93°F | 76°F | 66 ft | |
| Miami, FLFlorida | 1A | 48°F | 44°F | 91°F | 78°F | 13 ft | |
| Orlando, FLFlorida | 2A | 38°F | 33°F | 94°F | 77°F | 96 ft | |
| Tampa, FLFlorida | 2A | 41°F | 36°F | 92°F | 78°F | 19 ft | |
| Jacksonville, FLFlorida | 2A | 31°F | 27°F | 94°F | 77°F | 30 ft | |
| Atlanta, GAGeorgia | 3A | 22°F | 17°F | 91°F | 74°F | 1,010 ft | |
| Savannah, GAGeorgia | 2A | 29°F | 25°F | 94°F | 78°F | 50 ft | |
| Honolulu, HIHawaii | 1A | 64°F | 62°F | 89°F | 73°F | 15 ft | |
| Boise, IDIdaho | 5B | 11°F | 4°F | 96°F | 63°F | 2,858 ft | |
| Chicago (O'Hare), ILIllinois | 5A | -2°F | -7°F | 90°F | 74°F | 672 ft | |
| Springfield, ILIllinois | 4A | 2°F | -4°F | 91°F | 75°F | 597 ft | |
| Indianapolis, INIndiana | 5A | 4°F | -2°F | 89°F | 74°F | 792 ft | |
| Des Moines, IAIowa | 5A | -4°F | -10°F | 91°F | 75°F | 964 ft | |
| Wichita, KSKansas | 4A | 9°F | 3°F | 99°F | 74°F | 1,332 ft | |
| Louisville, KYKentucky | 4A | 13°F | 7°F | 91°F | 75°F | 497 ft | |
| New Orleans, LALouisiana | 2A | 35°F | 30°F | 93°F | 79°F | 4 ft | |
| Portland, MEMaine | 6A | 0°F | -6°F | 85°F | 70°F | 62 ft | |
| Baltimore, MDMaryland | 4A | 15°F | 10°F | 92°F | 75°F | 148 ft | |
| Boston (Logan), MAMassachusetts | 5A | 9°F | 4°F | 89°F | 73°F | 20 ft | |
| Detroit, MIMichigan | 5A | 6°F | 0°F | 89°F | 73°F | 645 ft | |
| Grand Rapids, MIMichigan | 5A | 4°F | -2°F | 88°F | 73°F | 794 ft | |
| Minneapolis / St. Paul, MNMinnesota | 6A | -11°F | -17°F | 89°F | 73°F | 841 ft | |
| Jackson, MSMississippi | 3A | 25°F | 20°F | 95°F | 77°F | 330 ft | |
| St. Louis, MOMissouri | 4A | 9°F | 2°F | 93°F | 76°F | 580 ft | |
| Kansas City, MOMissouri | 4A | 6°F | -1°F | 93°F | 75°F | 791 ft | |
| Billings, MTMontana | 6B | -12°F | -19°F | 92°F | 62°F | 3,567 ft | |
| Omaha, NENebraska | 5A | -2°F | -8°F | 92°F | 75°F | 983 ft | |
| Las Vegas, NVNevada | 3B | 34°F | 30°F | 108°F | 67°F | 2,180 ft | |
| Reno, NVNevada | 5B | 13°F | 7°F | 95°F | 59°F | 4,404 ft | |
| Concord, NHNew Hampshire | 6A | -5°F | -11°F | 88°F | 71°F | 342 ft | |
| Newark, NJNew Jersey | 4A | 14°F | 9°F | 92°F | 75°F | 30 ft | |
| Albuquerque, NMNew Mexico | 4B | 19°F | 14°F | 94°F | 61°F | 5,315 ft | |
| New York (JFK / Central Park), NYNew York | 4A | 15°F | 10°F | 89°F | 74°F | 32 ft | |
| Buffalo, NYNew York | 5A | 5°F | 0°F | 85°F | 71°F | 715 ft | |
| Albany, NYNew York | 5A | 1°F | -5°F | 88°F | 72°F | 290 ft | |
| Charlotte, NCNorth Carolina | 3A | 22°F | 17°F | 92°F | 74°F | 748 ft | |
| Raleigh / Durham, NCNorth Carolina | 3A | 20°F | 15°F | 92°F | 75°F | 435 ft | |
| Fargo, NDNorth Dakota | 7 | -19°F | -25°F | 89°F | 71°F | 900 ft | |
| Columbus, OHOhio | 5A | 6°F | 0°F | 89°F | 73°F | 812 ft | |
| Cleveland, OHOhio | 5A | 7°F | 2°F | 87°F | 72°F | 791 ft | |
| Cincinnati, OHOhio | 4A | 9°F | 3°F | 89°F | 74°F | 883 ft | |
| Oklahoma City, OKOklahoma | 3A | 14°F | 8°F | 99°F | 74°F | 1,290 ft | |
| Portland, OROregon | 4C | 27°F | 22°F | 88°F | 67°F | 30 ft | |
| Philadelphia, PAPennsylvania | 4A | 15°F | 11°F | 91°F | 75°F | 30 ft | |
| Pittsburgh, PAPennsylvania | 5A | 7°F | 2°F | 87°F | 72°F | 1,150 ft | |
| Providence, RIRhode Island | 5A | 10°F | 5°F | 88°F | 73°F | 55 ft | |
| Charleston, SCSouth Carolina | 2A | 29°F | 25°F | 93°F | 78°F | 46 ft | |
| Sioux Falls, SDSouth Dakota | 6A | -10°F | -16°F | 90°F | 73°F | 1,428 ft | |
| Nashville, TNTennessee | 4A | 17°F | 11°F | 92°F | 75°F | 590 ft | |
| Memphis, TNTennessee | 3A | 20°F | 15°F | 95°F | 77°F | 332 ft | |
| Houston (Bush), TXTexas | 2A | 33°F | 28°F | 96°F | 78°F | 96 ft | |
| Dallas / Fort Worth, TXTexas | 3A | 24°F | 19°F | 100°F | 75°F | 607 ft | |
| San Antonio, TXTexas | 2A | 32°F | 27°F | 99°F | 76°F | 809 ft | |
| Austin, TXTexas | 2A | 30°F | 25°F | 99°F | 75°F | 542 ft | |
| El Paso, TXTexas | 3B | 25°F | 21°F | 100°F | 64°F | 3,958 ft | |
| Salt Lake City, UTUtah | 5B | 14°F | 8°F | 97°F | 63°F | 4,227 ft | |
| Burlington, VTVermont | 6A | -7°F | -13°F | 86°F | 71°F | 334 ft | |
| Richmond, VAVirginia | 4A | 18°F | 13°F | 93°F | 76°F | 167 ft | |
| Norfolk / VA Beach, VAVirginia | 4A | 24°F | 19°F | 92°F | 77°F | 26 ft | |
| Seattle (Sea-Tac), WAWashington | 4C | 28°F | 23°F | 84°F | 66°F | 429 ft | |
| Spokane, WAWashington | 5B | 3°F | -4°F | 92°F | 62°F | 2,372 ft | |
| Charleston, WVWest Virginia | 4A | 12°F | 6°F | 89°F | 74°F | 981 ft | |
| Milwaukee, WIWisconsin | 5A | -1°F | -7°F | 87°F | 73°F | 672 ft | |
| Madison, WIWisconsin | 6A | -6°F | -12°F | 88°F | 73°F | 863 ft | |
| Cheyenne, WYWyoming | 6B | -4°F | -11°F | 88°F | 58°F | 6,156 ft | |
| Toronto (Pearson), ONOntario (CA) | 5A | 1°F | -4°F | 88°F | 72°F | 568 ft | |
| Montreal (Trudeau), QCQuebec (CA) | 6A | -7°F | -13°F | 86°F | 71°F | 118 ft | |
| Vancouver (YVR), BCBritish Columbia (CA) | 4C | 25°F | 20°F | 79°F | 64°F | 14 ft | |
| Calgary, ABAlberta (CA) | 7 | -18°F | -25°F | 84°F | 59°F | 3,556 ft |
📐 Design-Condition Percentiles & HVAC Sizing Context
Winter 99% vs 99.6% Design Dry Bulb
The 99.0% heating design dry-bulb temperature represents a statistical threshold: on average over a multi-year period of record, outdoor temperatures fall at or below this value during approximately 1% of the hours in a standard meteorological year (approx. 88 hours). Selection between 99.0% and 99.6% design conditions depends on the applicable design methodology, building occupancy, critical infrastructure criteria, local building code requirements, and owner/engineer design preferences.
Summer 0.4% vs 1.0% Design Dry Bulb & Coincident WB
The 0.4% summer cooling design dry-bulb represents the warm-season temperature exceeded on average during approximately 0.4% of annual hours (approx. 35 hours per year). Outdoor design dry-bulb and coincident wet-bulb temperatures provide essential boundary inputs for cooling-load calculations. Final equipment capacity and moisture removal performance depend on the complete sensible and latent load evaluation, equipment part-load curves, and selection methodologies (such as ACCA Manual S).
IECC Climate Zones (1A to 8)
The International Energy Conservation Code (IECC) and ANSI/ASHRAE/IES Standard 90.1 categorize regional climates into thermal zones (1 through 8) and moisture regimes: A (Moist/Humid), B (Dry/Arid), and C (Marine). IECC climate zones are used by applicable energy-code provisions to determine climate-dependent requirements (such as minimum building envelope insulation and equipment efficiency criteria) subject to adopted local code editions and amendments.
Use Design Conditions as Sizing Inputs
Apply Climatic Design Conditions to Engineering Calculation Models
BTU Heating & Cooling Load Calculator
Apply local 0.4% summer cooling DB and 99% winter heating DB as design inputs for whole-house sensible and latent heat load screening models.
Building Heat Loss & Infiltration Sizer
Input 99% winter design dry-bulb temperatures as design conditions to estimate conductive envelope transmission (U · A · ΔT) and air infiltration losses.
Heat Pump Sizing & Balance Point Tool
Evaluate heat pump capacity curves down to 99% winter design temperatures to estimate thermal balance points and auxiliary electric heat strip requirements.