# Climate Design Data Workflow for Tucson, AZ

> A source-first workflow for retrieving and recording building-design climate conditions for Tucson, AZ without mixing climate normals, code zones, and HVAC design percentiles.

- Canonical: https://harth.build/resources/climate-data/climate-design-data-workflow-tucson-az/
- Last updated: 2026-08-31
- Data source: Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 32.2226° N (America/Phoenix) are approximate routing references. Figures are illustrative — confirm the representative station and current edition. Climate screening data from the [NASA POWER Climatology API documentation](https://power.larc.nasa.gov/docs/services/api/temporal/climatology/) and [exact point response](https://power.larc.nasa.gov/api/temporal/climatology/point?parameters=T2M%2CT2M_MAX%2CT2M_MIN%2CRH2M%2CPRECTOTCORR%2CWS10M&community=SB&longitude=-110.9747&latitude=32.2226&format=JSON), 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.

## Key facts

| Fact | Value |
| --- | --- |
| NASA POWER climatology | 20-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2020) (API v2.9.7; LST) |
| Annual mean temperature | 19.8 °C (2 m gridded climatology; not a design percentile) |
| Highest monthly maximum | 44.8 °C (June) (monthly climatological statistic) |
| Lowest monthly minimum | -8.1 °C (February) (monthly climatological statistic) |
| Annual relative humidity | 37.6% (2 m gridded climatology) |
| Annual corrected precipitation | 0.88 mm/day (climatological daily rate) |
| Annual wind speed | 3.58 m/s (10 m gridded climatology; not a structural design wind speed) |

## Direct answer

NASA POWER's 2001–2020 climatology at the Tucson, AZ reference point reports an annual mean 2 m temperature of 19.8 °C and relative humidity of 37.6%. The highest monthly maximum is 44.8 °C in June, while the lowest monthly minimum is -8.1 °C in February; 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 0.88 mm/day and annual 10 m wind speed is 3.58 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](https://www.linkedin.com/company/harth-build) · 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.

| Field | Required record |
| --- | --- |
| Station | Name, ID, coordinates and elevation |
| Source | Publisher, edition and licensed/public status |
| Heating | 99.6% and 99% dry-bulb |
| Cooling | 0.4%, 1% and 2% dry-bulb plus coincident wet-bulb |
| Moisture | Dew-point or humidity design condition used |
| Code | Adopted edition, amendments and effective date |

## Tucson, AZ NASA POWER monthly climate screening table

| Month | Mean °C | Monthly max °C | Monthly min °C | RH % | Precipitation mm/day | Wind at 10 m m/s |
| --- | ---: | ---: | ---: | ---: | ---: | ---: |
| January | 10.00 | 27.44 | -6.51 | 46.37 | 0.79 | 3.73 |
| February | 11.22 | 30.19 | -8.11 | 44.07 | 0.74 | 3.72 |
| March | 14.91 | 34.20 | -3.41 | 36.75 | 0.45 | 3.78 |
| April | 18.54 | 37.69 | 1.43 | 28.36 | 0.26 | 4.12 |
| May | 23.43 | 42.15 | 4.97 | 21.97 | 0.13 | 4.04 |
| June | 29.28 | 44.84 | 12.72 | 18.95 | 0.28 | 3.86 |
| July | 29.40 | 43.82 | 16.69 | 42.41 | 2.68 | 2.97 |
| August | 28.65 | 42.18 | 17.81 | 46.78 | 2.08 | 2.62 |
| September | 26.37 | 41.55 | 11.73 | 42.95 | 1.34 | 3.15 |
| October | 20.93 | 38.55 | 1.11 | 37.48 | 0.47 | 3.41 |
| November | 15.02 | 33.59 | -5.23 | 38.53 | 0.48 | 3.76 |
| December | 9.72 | 28.00 | -5.50 | 46.19 | 0.86 | 3.78 |

![Monthly mean, maximum and minimum air temperature for Climate Design Data Workflow for Tucson, AZ](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/climate-data/climate-design-data-workflow-tucson-az/chart-temperature-1344.webp)

*Monthly air temperature for Climate Design Data Workflow for Tucson, AZ, plotted from the table above.*

![Mean daily precipitation by month for Climate Design Data Workflow for Tucson, AZ](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/climate-data/climate-design-data-workflow-tucson-az/chart-precipitation-1344.webp)

*Mean daily precipitation for Climate Design Data Workflow for Tucson, AZ, plotted from the table above.*

## Month-by-month climate interpretation

- **January:** mean temperature 10.00 °C is 9.83 °C below the annual mean; the monthly max–min span is 33.95 °C. Relative humidity is 46.37% (8.79 points above annual), while corrected precipitation at 0.79 mm/day is 0.09 mm/day drier than the annual daily rate.
- **February:** mean temperature 11.22 °C is 8.61 °C below the annual mean; the monthly max–min span is 38.30 °C. Relative humidity is 44.07% (6.49 points above annual), while corrected precipitation at 0.74 mm/day is 0.14 mm/day drier than the annual daily rate.
- **March:** mean temperature 14.91 °C is 4.92 °C below the annual mean; the monthly max–min span is 37.61 °C. Relative humidity is 36.75% (0.83 points below annual), while corrected precipitation at 0.45 mm/day is 0.43 mm/day drier than the annual daily rate.
- **April:** mean temperature 18.54 °C is 1.29 °C below the annual mean; the monthly max–min span is 36.26 °C. Relative humidity is 28.36% (9.22 points below annual), while corrected precipitation at 0.26 mm/day is 0.62 mm/day drier than the annual daily rate.
- **May:** mean temperature 23.43 °C is 3.60 °C above the annual mean; the monthly max–min span is 37.18 °C. Relative humidity is 21.97% (15.61 points below annual), while corrected precipitation at 0.13 mm/day is 0.75 mm/day drier than the annual daily rate.
- **June:** mean temperature 29.28 °C is 9.45 °C above the annual mean; the monthly max–min span is 32.12 °C. Relative humidity is 18.95% (18.63 points below annual), while corrected precipitation at 0.28 mm/day is 0.60 mm/day drier than the annual daily rate.
- **July:** mean temperature 29.40 °C is 9.57 °C above the annual mean; the monthly max–min span is 27.13 °C. Relative humidity is 42.41% (4.83 points above annual), while corrected precipitation at 2.68 mm/day is 1.80 mm/day wetter than the annual daily rate.
- **August:** mean temperature 28.65 °C is 8.82 °C above the annual mean; the monthly max–min span is 24.37 °C. Relative humidity is 46.78% (9.20 points above annual), while corrected precipitation at 2.08 mm/day is 1.20 mm/day wetter than the annual daily rate.
- **September:** mean temperature 26.37 °C is 6.54 °C above the annual mean; the monthly max–min span is 29.82 °C. Relative humidity is 42.95% (5.37 points above annual), while corrected precipitation at 1.34 mm/day is 0.46 mm/day wetter than the annual daily rate.
- **October:** mean temperature 20.93 °C is 1.10 °C above the annual mean; the monthly max–min span is 37.44 °C. Relative humidity is 37.48% (0.10 points below annual), while corrected precipitation at 0.47 mm/day is 0.41 mm/day drier than the annual daily rate.
- **November:** mean temperature 15.02 °C is 4.81 °C below the annual mean; the monthly max–min span is 38.82 °C. Relative humidity is 38.53% (0.95 points above annual), while corrected precipitation at 0.48 mm/day is 0.40 mm/day drier than the annual daily rate.
- **December:** mean temperature 9.72 °C is 10.11 °C below the annual mean; the monthly max–min span is 33.50 °C. Relative humidity is 46.19% (8.61 points above annual), while corrected precipitation at 0.86 mm/day is 0.02 mm/day drier than the annual daily rate.

Harth retrieved this point climatology from NASA POWER API v2.9.7 for location record us:tucson-az. 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](https://harth.build/resources/climate-data.md)
- [ASHRAE / IECC Climate Zones Explained (Zones 1–8, A/B/C)](https://harth.build/resources/climate-data/ashrae-climate-zones-explained.md)
- [Heating & Cooling Design Temperatures (99%, 1% / 0.4%)](https://harth.build/resources/climate-data/heating-and-cooling-design-temperatures.md)
- [Climate Design Data Workflow for Albuquerque, NM](https://harth.build/resources/climate-data/climate-design-data-workflow-albuquerque-nm.md)
- [Climate Design Data Workflow for Las Vegas, NV](https://harth.build/resources/climate-data/climate-design-data-workflow-las-vegas-nv.md)
- [Sun Path & Solar Angles for Tucson, AZ](https://harth.build/resources/solar-data/sun-path-and-solar-angles-tucson-az.md)

## Sources and method

Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 32.2226° N (America/Phoenix) are approximate routing references. Figures are illustrative — confirm the representative station and current edition. Climate screening data from the [NASA POWER Climatology API documentation](https://power.larc.nasa.gov/docs/services/api/temporal/climatology/) and [exact point response](https://power.larc.nasa.gov/api/temporal/climatology/point?parameters=T2M%2CT2M_MAX%2CT2M_MIN%2CRH2M%2CPRECTOTCORR%2CWS10M&community=SB&longitude=-110.9747&latitude=32.2226&format=JSON), 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](https://power.larc.nasa.gov/docs/services/api/temporal/climatology/)

- [power.larc.nasa.gov](https://power.larc.nasa.gov/api/temporal/climatology/point?parameters=T2M%2CT2M_MAX%2CT2M_MIN%2CRH2M%2CPRECTOTCORR%2CWS10M&community=SB&longitude=-110.9747&latitude=32.2226&format=JSON)

## Frequently asked questions

### What does NASA POWER climatology show for Tucson, AZ?

For the Tucson, AZ reference point, the 2001–2020 NASA POWER climatology reports 19.8 °C annual mean temperature, 37.6% relative humidity and 0.88 mm/day corrected precipitation. The monthly maximum peaks at 44.8 °C in June.

### Can the Tucson, AZ climatology replace project design temperatures or an hourly weather file?

No. The Tucson, AZ response is gridded monthly climatology; its lowest monthly minimum of -8.1 °C in February is not a code percentile or observed site extreme. Verify elevation, local exposure, the required weather file or design-condition source and the current adopted code.

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