Idaho design temperatures
Outdoor heating and cooling design conditions for 6 Idaho weather stations. Choose the station nearest to you in distance and elevation, and check whether your building department specifies its own values.
| Station | Elevation | 99.6 % heating | 99 % heating | 1 % cooling / MCWB | 0.4 % cooling / MCWB | Use it |
|---|---|---|---|---|---|---|
| BoiseWMO 726810 · 1973–1996 | 2,868 ft | 1 °F | 8 °F | 94 / 63 °F | 97 / 64 °F | Load calculator |
| Coeur D'AleneWMO 727834 · 1979–1996 | 2,320 ft | 3 °F | 9 °F | 88 / 63 °F | 92 / 64 °F | Load calculator |
| Idaho Falls/FanningWMO 725785 · 1973–1996 | 4,741 ft | −11 °F | −4 °F | 89 / 60 °F | 91 / 61 °F | Load calculator |
| LewistonWMO 727830 · 1973–1996 | 1,437 ft | 6 °F | 14 °F | 94 / 64 °F | 98 / 65 °F | Load calculator |
| Mountain Home AFBWMO 726815 · 1967–1996 | 2,996 ft | 3 °F | 9 °F | 96 / 62 °F | 99 / 64 °F | Load calculator |
| PocatelloWMO 725780 · 1973–1996 | 4,479 ft | −7 °F | −1 °F | 91 / 61 °F | 93 / 61 °F | Load calculator |
Using these values
- Heat-loss calculations for homes commonly use the 99 % heating value, and cooling loads the 1 % dry bulb with its mean coincident wet bulb (MCWB). The 99.6 % and 0.4 % values are more conservative.
- “Load calculator” opens the heating and cooling load calculator with that station’s 99 % and 1 % temperatures and its design moisture difference (outdoor air at the 1 % condition versus 75 °F, 50 % RH indoors, at the station’s elevation).
- Source: U.S. Air Force Combat Climatology Center and NOAA National Climatic Data Center, Engineering Weather Data (1999; public domain). Each station’s period of record is shown under its name; they end by 1996, and the climate has warmed since, so check local requirements before relying on a value for a permit.