Iowa design temperatures
Outdoor heating and cooling design conditions for 7 Iowa 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 |
|---|---|---|---|---|---|---|
| BurlingtonWMO 725455 · 1973–1996 | 699 ft | −5 °F | 0 °F | 90 / 76 °F | 93 / 77 °F | Load calculator |
| Cedar RapidsWMO 725450 · 1973–1996 | 869 ft | −11 °F | −5 °F | 89 / 74 °F | 92 / 76 °F | Load calculator |
| Des MoinesWMO 725460 · 1973–1996 | 965 ft | −8 °F | −3 °F | 91 / 75 °F | 94 / 76 °F | Load calculator |
| Fort DodgeWMO 725490 · 1973–1996 | 1,165 ft | −13 °F | −8 °F | 88 / 73 °F | 91 / 75 °F | Load calculator |
| Mason CityWMO 725485 · 1973–1996 | 1,214 ft | −16 °F | −10 °F | 88 / 73 °F | 92 / 75 °F | Load calculator |
| Sioux CityWMO 725570 · 1973–1996 | 1,102 ft | −11 °F | −6 °F | 91 / 74 °F | 94 / 75 °F | Load calculator |
| WaterlooWMO 725480 · 1967–1996 | 879 ft | −15 °F | −9 °F | 89 / 73 °F | 92 / 75 °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.