Climate Design Data Workflow for Houston, TX

Direct answer

NASA POWER's 2001–2020 climatology at the Houston, TX reference point reports an annual mean 2 m temperature of 20.4 °C and relative humidity of 76.8%. The highest monthly maximum is 42.6 °C in August, while the lowest monthly minimum is -7.8 °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 3.41 mm/day and annual 10 m wind speed is 3.28 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.

Houston, TX NASA POWER monthly climate screening table

Month-by-month climate interpretation

• January: mean temperature 10.27 °C is 10.18 °C below the annual mean; the monthly max–min span is 33.97 °C. Relative humidity is 80.62% (3.84 points above annual), while corrected precipitation at 2.88 mm/day is 0.53 mm/day drier than the annual daily rate.
• February: mean temperature 12.50 °C is 7.95 °C below the annual mean; the monthly max–min span is 36.95 °C. Relative humidity is 81.37% (4.59 points above annual), while corrected precipitation at 2.46 mm/day is 0.95 mm/day drier than the annual daily rate.
• March: mean temperature 16.49 °C is 3.96 °C below the annual mean; the monthly max–min span is 37.10 °C. Relative humidity is 79.70% (2.92 points above annual), while corrected precipitation at 2.73 mm/day is 0.68 mm/day drier than the annual daily rate.
• April: mean temperature 20.40 °C is 0.05 °C below the annual mean; the monthly max–min span is 35.06 °C. Relative humidity is 77.03% (0.25 points above annual), while corrected precipitation at 2.91 mm/day is 0.50 mm/day drier than the annual daily rate.
• May: mean temperature 24.64 °C is 4.19 °C above the annual mean; the monthly max–min span is 32.29 °C. Relative humidity is 74.45% (2.33 points below annual), while corrected precipitation at 3.83 mm/day is 0.42 mm/day wetter than the annual daily rate.
• June: mean temperature 27.96 °C is 7.51 °C above the annual mean; the monthly max–min span is 24.79 °C. Relative humidity is 73.06% (3.72 points below annual), while corrected precipitation at 4.20 mm/day is 0.79 mm/day wetter than the annual daily rate.
• July: mean temperature 28.50 °C is 8.05 °C above the annual mean; the monthly max–min span is 21.99 °C. Relative humidity is 74.52% (2.26 points below annual), while corrected precipitation at 3.56 mm/day is 0.15 mm/day wetter than the annual daily rate.
• August: mean temperature 29.03 °C is 8.58 °C above the annual mean; the monthly max–min span is 26.03 °C. Relative humidity is 72.02% (4.76 points below annual), while corrected precipitation at 4.03 mm/day is 0.62 mm/day wetter than the annual daily rate.
• September: mean temperature 26.21 °C is 5.76 °C above the annual mean; the monthly max–min span is 30.26 °C. Relative humidity is 75.34% (1.44 points below annual), while corrected precipitation at 3.93 mm/day is 0.52 mm/day wetter than the annual daily rate.
• October: mean temperature 21.38 °C is 0.93 °C above the annual mean; the monthly max–min span is 33.40 °C. Relative humidity is 75.09% (1.69 points below annual), while corrected precipitation at 4.13 mm/day is 0.72 mm/day wetter than the annual daily rate.
• November: mean temperature 15.91 °C is 4.54 °C below the annual mean; the monthly max–min span is 34.32 °C. Relative humidity is 78.18% (1.40 points above annual), while corrected precipitation at 3.14 mm/day is 0.27 mm/day drier than the annual daily rate.
• December: mean temperature 11.67 °C is 8.78 °C below the annual mean; the monthly max–min span is 32.94 °C. Relative humidity is 80.27% (3.49 points above annual), while corrected precipitation at 3.09 mm/day is 0.32 mm/day drier than the annual daily rate.

Harth retrieved this point climatology from NASA POWER API v2.9.7 for location record us:houston-tx. 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 Austin, TX
• Climate Design Data Workflow for Dallas, TX
• Sun Path & Solar Angles for Houston, TX

Sources and method

Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 29.7604° N (America/Chicago) 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