Climate Design Data Workflow for Boise, ID

Direct answer

NASA POWER's 2001–2020 climatology at the Boise, ID reference point reports an annual mean 2 m temperature of 10.7 °C and relative humidity of 55.0%. The highest monthly maximum is 43.4 °C in July, while the lowest monthly minimum is -22.7 °C in January; these are screening statistics, not code design temperatures. The point response uses LST and the 20-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2020); its annual corrected precipitation is 1.06 mm/day and annual 10 m wind speed is 3.26 m/s. Use the monthly series to screen source selection before applying project design conditions. NASA POWER is gridded climatology: verify elevation, microclimate, urban exposure, station or weather-file suitability, current code edition and the authority's required source before design use.

Content and cited inputs reviewed by Harth team · Published 2026-08-17 · Updated 2026-08-31.

Which climate inputs control the design?

1. Confirm the project jurisdiction and adopted energy-code edition.
2. Select the authoritative station and record why it applies.
3. Record heating dry-bulb percentiles and cooling dry-bulb with coincident moisture conditions.
4. Keep IP/SI units, edition, observation period and retrieval date with every value.
5. Separate climate-zone envelope requirements from HVAC sizing conditions.

Boise, ID NASA POWER monthly climate screening table

Month-by-month climate interpretation

• January: mean temperature -1.71 °C is 12.41 °C below the annual mean; the monthly max–min span is 36.63 °C. Relative humidity is 81.26% (26.27 points above annual), while corrected precipitation at 1.65 mm/day is 0.59 mm/day wetter than the annual daily rate.
• February: mean temperature 0.72 °C is 9.98 °C below the annual mean; the monthly max–min span is 28.78 °C. Relative humidity is 73.38% (18.39 points above annual), while corrected precipitation at 1.26 mm/day is 0.20 mm/day wetter than the annual daily rate.
• March: mean temperature 5.04 °C is 5.66 °C below the annual mean; the monthly max–min span is 32.38 °C. Relative humidity is 65.36% (10.37 points above annual), while corrected precipitation at 1.52 mm/day is 0.46 mm/day wetter than the annual daily rate.
• April: mean temperature 8.65 °C is 2.05 °C below the annual mean; the monthly max–min span is 35.27 °C. Relative humidity is 58.45% (3.46 points above annual), while corrected precipitation at 1.17 mm/day is 0.11 mm/day wetter than the annual daily rate.
• May: mean temperature 14.29 °C is 3.59 °C above the annual mean; the monthly max–min span is 40.71 °C. Relative humidity is 51.72% (3.27 points below annual), while corrected precipitation at 1.21 mm/day is 0.15 mm/day wetter than the annual daily rate.
• June: mean temperature 19.37 °C is 8.67 °C above the annual mean; the monthly max–min span is 40.23 °C. Relative humidity is 44.22% (10.77 points below annual), while corrected precipitation at 0.76 mm/day is 0.30 mm/day drier than the annual daily rate.
• July: mean temperature 25.68 °C is 14.98 °C above the annual mean; the monthly max–min span is 35.38 °C. Relative humidity is 31.85% (23.14 points below annual), while corrected precipitation at 0.21 mm/day is 0.85 mm/day drier than the annual daily rate.
• August: mean temperature 24.52 °C is 13.82 °C above the annual mean; the monthly max–min span is 35.01 °C. Relative humidity is 28.81% (26.18 points below annual), while corrected precipitation at 0.23 mm/day is 0.83 mm/day drier than the annual daily rate.
• September: mean temperature 18.78 °C is 8.08 °C above the annual mean; the monthly max–min span is 37.53 °C. Relative humidity is 34.24% (20.75 points below annual), while corrected precipitation at 0.46 mm/day is 0.60 mm/day drier than the annual daily rate.
• October: mean temperature 10.58 °C is 0.12 °C below the annual mean; the monthly max–min span is 41.28 °C. Relative humidity is 48.88% (6.11 points below annual), while corrected precipitation at 0.87 mm/day is 0.19 mm/day drier than the annual daily rate.
• November: mean temperature 3.44 °C is 7.26 °C below the annual mean; the monthly max–min span is 37.44 °C. Relative humidity is 64.34% (9.35 points above annual), while corrected precipitation at 1.34 mm/day is 0.28 mm/day wetter than the annual daily rate.
• December: mean temperature -1.60 °C is 12.30 °C below the annual mean; the monthly max–min span is 35.39 °C. Relative humidity is 78.37% (23.38 points above annual), while corrected precipitation at 2.11 mm/day is 1.05 mm/day wetter than the annual daily rate.

Harth retrieved this point climatology from NASA POWER API v2.9.7 for location record us:boise-id. It is a reproducible screening dataset, not an hourly weather file, forecast, code design condition or substitute for local professional review.

Where can you explore related guidance?

• Explore all climate data guidance
• ASHRAE / IECC Climate Zones Explained (Zones 1–8, A/B/C)
• Heating & Cooling Design Temperatures (99%, 1% / 0.4%)
• Climate Design Data Workflow for Salt Lake City, UT
• Climate Design Data Workflow for Portland, OR
• Sun Path & Solar Angles for Boise, ID

Sources and method

Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 43.6150° N (America/Boise) are approximate routing references. Figures are illustrative — confirm the representative station and current edition. Climate screening data from the NASA POWER Climatology API documentation and exact point response, retrieved 2026-08-31; source period: 20-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2020). NASA POWER values are gridded screening statistics, not code design conditions or guaranteed local observations.

Source links

• power.larc.nasa.gov

• power.larc.nasa.gov