Summer Heat scores a destination by its annual number of days above 90°F. Fewer days receive a higher score. The measure has coverage for 987 destinations and supplies the required summer input used by Climate Comfort.
It is a broad destination-comparison measure, not a forecast or an assessment of personal heat safety.
Summer Heat thresholds
The input is the annual count of days above 90°F. Retirement Lists converts that count to a score as follows:
| Annual days above 90°F | Summer Heat score |
|---|---|
| 10 or fewer | 95 |
| 11–30 | 82 |
| 31–60 | 68 |
| 61–100 | 48 |
| More than 100 | 25 |
No interpolation between bands is specified.
Temperature evidence by geography
Most published Summer Heat inputs, covering roughly 938 to 939 destinations, use NASA POWER daily evidence from January 1, 2019 through December 31, 2023.
Another 48 temperature rows use NOAA Global Historical Climatology Network Daily station evidence from January 1, 1991 through December 31, 2020. Of those rows, 39 are direct-city records and nine are estimated or based on nearby evidence.
Fukuoka uses Japan Meteorological Agency evidence from station 47807 for January 1, 1991 through December 31, 2020. The station is 2.59 kilometers from Fukuoka City Hall, and the evidence contains 10,958 complete daily records. It supports Fukuoka’s days above 90°F and the resulting heat measure only.
Included and excluded information
Summer Heat includes only the annual frequency of days above 90°F represented by the applicable evidence source.
It does not separately measure the duration or intensity of heat waves, neighborhood microclimates, the cooling performance of a particular home, or an individual’s heat tolerance.
Missing data and product use
A destination needs a supported annual-days-above-90°F input to receive a Summer Heat score. Missing required source evidence fails closed and is not replaced with an assumed value.
Summer Heat has full standalone decision eligibility for all 987 covered destinations. It may be displayed and used in filters, sorting, Fit, hard constraints, and Compare. It also supplies a required input to Climate Comfort. If that summer input is missing, Climate Comfort fails closed.
Data periods and freshness
The applicable data period depends on the evidence source:
- NASA POWER daily evidence: January 1, 2019–December 31, 2023.
- NOAA GHCNd evidence: January 1, 1991–December 31, 2020.
- JMA Fukuoka evidence: January 1, 1991–December 31, 2020.
These labels describe observation periods. No publisher update dates, source-update dates, update cadence, or editorial review date are recorded.
Limits of the score
Two destinations with the same score can still experience heat differently. The threshold bands do not show whether hot days arrive together in a prolonged heat wave, how temperatures vary by neighborhood, or whether a home has effective cooling.
Personal heat tolerance and health circumstances also fall outside this methodology.
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Included, excluded, and eligibility contract
| Item | Contract |
|---|---|
| Included | Annual count of days above 90°F |
| Excluded | Heat-wave duration, neighborhood microclimate, home cooling, and personal heat tolerance |
| Missing behavior | Missing required source evidence means no Summer Heat score; the related Climate Comfort result fails closed |
| Coverage | 987 destinations |
| Display eligibility | Eligible for all 987 destinations |
| Decision eligibility | Eligible for filter, sort, Fit, hard constraints, and Compare for all 987 destinations |
Source ledger
| Organization | URL | Supported claim or input | Geography | Data period | Observed/source-updated | Last reviewed | Evidence type | Limitation |
|---|---|---|---|---|---|---|---|---|
| NASA POWER | https://power.larc.nasa.gov/docs/services/api/temporal/daily/ | Daily temperature evidence supporting annual days above 90°F | Roughly 938–939 destinations | 2019-01-01–2023-12-31 | Source-update date unavailable | Not recorded | Daily modeled/reanalysis delivery documentation | Coverage count is approximate; local microclimates may not be represented |
| NOAA NCEI | https://www.ncei.noaa.gov/data/global-historical-climatology-network-daily/access/{STATION_ID}.csv | Station evidence supporting annual days above 90°F | 48 rows: 39 direct-city and nine estimated or nearby | 1991-01-01–2020-12-31 | Source-update date unavailable | Not recorded | Daily station files | Nearby or estimated rows may not represent conditions within the destination |
| Japan Meteorological Agency | https://www.data.jma.go.jp/stats/etrn/view/nml_sfc_ym.php?block_no=47807&day=&month=&prec_no=82&view=a2s&year= | Station-normal context for Fukuoka station 47807 | Fukuoka, Japan | 1991-01-01–2020-12-31 | Source-update date unavailable | Not recorded | Official station normals | Applies only to Fukuoka and does not support other destinations |
| Japan Meteorological Agency | https://www.data.jma.go.jp/risk/obsdl/show/table | Daily export supporting Fukuoka days above 90°F | Fukuoka, Japan; station 47807 | 1991-01-01–2020-12-31 | Source-update date unavailable | Not recorded | Official daily station export | Station is 2.59 km from City Hall; evidence does not describe every neighborhood |
Sources and review
- NASA POWER
Daily temperature evidence supporting annual days above 90°F.
- NOAA NCEI
Station evidence supporting annual days above 90°F.
- Japan Meteorological Agency
Station-normal context for Fukuoka station 47807.
- Japan Meteorological Agency
Daily export supporting Fukuoka days above 90°F.