# Climate Design Data Workflow for Anchorage, AK

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

- Canonical: https://harth.build/resources/climate-data/climate-design-data-workflow-anchorage-ak/
- Last updated: 2026-08-31
- Data source: Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 61.2181° N (America/Anchorage) 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=-149.9003&latitude=61.2181&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 | 1.9 °C (2 m gridded climatology; not a design percentile) |
| Highest monthly maximum | 27.1 °C (July) (monthly climatological statistic) |
| Lowest monthly minimum | -26.5 °C (March) (monthly climatological statistic) |
| Annual relative humidity | 85.6% (2 m gridded climatology) |
| Annual corrected precipitation | 2.25 mm/day (climatological daily rate) |
| Annual wind speed | 2.76 m/s (10 m gridded climatology; not a structural design wind speed) |

## Direct answer

NASA POWER's 2001–2020 climatology at the Anchorage, AK reference point reports an annual mean 2 m temperature of 1.9 °C and relative humidity of 85.6%. The highest monthly maximum is 27.1 °C in July, while the lowest monthly minimum is -26.5 °C in March; 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 2.25 mm/day and annual 10 m wind speed is 2.76 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 |

## Anchorage, AK 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 | -8.26 | 3.36 | -25.72 | 92.02 | 1.71 | 3.16 |
| February | -6.54 | 2.95 | -21.95 | 90.52 | 1.81 | 3.18 |
| March | -5.60 | 6.20 | -26.47 | 87.84 | 1.26 | 2.96 |
| April | 0.39 | 13.16 | -17.21 | 82.39 | 1.27 | 2.68 |
| May | 6.45 | 20.83 | -7.26 | 77.92 | 1.52 | 2.54 |
| June | 11.10 | 25.95 | 2.61 | 78.58 | 1.97 | 2.28 |
| July | 13.54 | 27.11 | 5.21 | 80.63 | 2.69 | 2.17 |
| August | 12.66 | 26.81 | 3.31 | 81.75 | 3.55 | 2.31 |
| September | 8.31 | 18.91 | -2.83 | 83.57 | 3.94 | 2.72 |
| October | 2.00 | 12.53 | -13.85 | 87.83 | 2.82 | 2.87 |
| November | -5.25 | 6.58 | -20.78 | 91.93 | 2.37 | 3.07 |
| December | -6.99 | 3.63 | -24.83 | 92.99 | 2.07 | 3.19 |

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

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

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

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

## Month-by-month climate interpretation

- **January:** mean temperature -8.26 °C is 10.12 °C below the annual mean; the monthly max–min span is 29.08 °C. Relative humidity is 92.02% (6.38 points above annual), while corrected precipitation at 1.71 mm/day is 0.54 mm/day drier than the annual daily rate.
- **February:** mean temperature -6.54 °C is 8.40 °C below the annual mean; the monthly max–min span is 24.90 °C. Relative humidity is 90.52% (4.88 points above annual), while corrected precipitation at 1.81 mm/day is 0.44 mm/day drier than the annual daily rate.
- **March:** mean temperature -5.60 °C is 7.46 °C below the annual mean; the monthly max–min span is 32.67 °C. Relative humidity is 87.84% (2.20 points above annual), while corrected precipitation at 1.26 mm/day is 0.99 mm/day drier than the annual daily rate.
- **April:** mean temperature 0.39 °C is 1.47 °C below the annual mean; the monthly max–min span is 30.37 °C. Relative humidity is 82.39% (3.25 points below annual), while corrected precipitation at 1.27 mm/day is 0.98 mm/day drier than the annual daily rate.
- **May:** mean temperature 6.45 °C is 4.59 °C above the annual mean; the monthly max–min span is 28.09 °C. Relative humidity is 77.92% (7.72 points below annual), while corrected precipitation at 1.52 mm/day is 0.73 mm/day drier than the annual daily rate.
- **June:** mean temperature 11.10 °C is 9.24 °C above the annual mean; the monthly max–min span is 23.34 °C. Relative humidity is 78.58% (7.06 points below annual), while corrected precipitation at 1.97 mm/day is 0.28 mm/day drier than the annual daily rate.
- **July:** mean temperature 13.54 °C is 11.68 °C above the annual mean; the monthly max–min span is 21.90 °C. Relative humidity is 80.63% (5.01 points below annual), while corrected precipitation at 2.69 mm/day is 0.44 mm/day wetter than the annual daily rate.
- **August:** mean temperature 12.66 °C is 10.80 °C above the annual mean; the monthly max–min span is 23.50 °C. Relative humidity is 81.75% (3.89 points below annual), while corrected precipitation at 3.55 mm/day is 1.30 mm/day wetter than the annual daily rate.
- **September:** mean temperature 8.31 °C is 6.45 °C above the annual mean; the monthly max–min span is 21.74 °C. Relative humidity is 83.57% (2.07 points below annual), while corrected precipitation at 3.94 mm/day is 1.69 mm/day wetter than the annual daily rate.
- **October:** mean temperature 2.00 °C is 0.14 °C above the annual mean; the monthly max–min span is 26.38 °C. Relative humidity is 87.83% (2.19 points above annual), while corrected precipitation at 2.82 mm/day is 0.57 mm/day wetter than the annual daily rate.
- **November:** mean temperature -5.25 °C is 7.11 °C below the annual mean; the monthly max–min span is 27.36 °C. Relative humidity is 91.93% (6.29 points above annual), while corrected precipitation at 2.37 mm/day is 0.12 mm/day wetter than the annual daily rate.
- **December:** mean temperature -6.99 °C is 8.85 °C below the annual mean; the monthly max–min span is 28.46 °C. Relative humidity is 92.99% (7.35 points above annual), while corrected precipitation at 2.07 mm/day is 0.18 mm/day drier than the annual daily rate.

Harth retrieved this point climatology from NASA POWER API v2.9.7 for location record us:anchorage-ak. 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 Seattle, WA](https://harth.build/resources/climate-data/climate-design-data-workflow-seattle-wa.md)
- [Climate Design Data Workflow for Portland, OR](https://harth.build/resources/climate-data/climate-design-data-workflow-portland-or.md)
- [Sun Path & Solar Angles for Anchorage, AK](https://harth.build/resources/solar-data/sun-path-and-solar-angles-anchorage-ak.md)

## Sources and method

Licensed ASHRAE Climatic Design Information / Standard 169 station data plus the locally adopted energy code. Coordinates 61.2181° N (America/Anchorage) 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=-149.9003&latitude=61.2181&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=-149.9003&latitude=61.2181&format=JSON)

## Frequently asked questions

### What does NASA POWER climatology show for Anchorage, AK?

For the Anchorage, AK reference point, the 2001–2020 NASA POWER climatology reports 1.9 °C annual mean temperature, 85.6% relative humidity and 2.25 mm/day corrected precipitation. The monthly maximum peaks at 27.1 °C in July.

### Can the Anchorage, AK climatology replace project design temperatures or an hourly weather file?

No. The Anchorage, AK response is gridded monthly climatology; its lowest monthly minimum of -26.5 °C in March 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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