FA-70981 / Weather index computation / Open access

WBGT heat flag: Fahrenheit conversion · case 01

Every site shows a black flag.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The Celsius to Fahrenheit conversion adds 32 before scaling.

VERIFIED REPAIR

Convert with w*9/5 + 32.

Unsuccessful approach: Using 5/9 converts in the wrong direction and nearly every site reads white.

Case contract

Inputs natural wet bulb, globe and dry bulb in degC and whether the site is in sun. Sun: WBGT = 0.7Tw + 0.2Tg + 0.1Td; shade/indoor: 0.7Tw + 0.3Tg; round to 0.1 degC. Convert the rounded value to degF (x*9/5+32) and flag: <80 white, <85 green, <88 yellow, <90 red, else black.

Why this case matters

Training and work/rest schedules follow the WBGT flag colour.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    w = round(w, 1)
    wf = (w + 32) * 9 / 5
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']]], [['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']]], [['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']]], [['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 27 Tg 29.4 Td 30 sun', [27, 29.4, 30, True], [27.8, 'green']], ['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'black']`	`[22.5, 'white']`	Failed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'black']`	`[23.0, 'white']`	Failed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'black']`	`[26.8, 'green']`	Failed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'black']`	`[27.3, 'green']`	Failed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'black']`	`[28.6, 'green']`	Failed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'black']`	`[29.5, 'yellow']`	Failed
Tw 26 Tg 38 Td 30 sun	`[28.8, 'black']`	`[28.8, 'green']`	Failed
Tw 26 Tg 38 Td 30 indoor	`[29.6, 'black']`	`[29.6, 'yellow']`	Failed

SHA-256 / dfc7149f6de2421f487301fde4f0a743484ef5d61531319b8604e99e660ee09d

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    w = round(w, 1)
    wf = w * 5 / 9 + 32
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']]], [['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']]], [['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']]], [['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 27 Tg 29.4 Td 30 sun', [27, 29.4, 30, True], [27.8, 'green']], ['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'white']`	`[22.5, 'white']`	Passed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'white']`	`[23.0, 'white']`	Passed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'white']`	`[26.8, 'green']`	Failed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'white']`	`[27.3, 'green']`	Failed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'white']`	`[28.6, 'green']`	Failed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'white']`	`[29.5, 'yellow']`	Failed
Tw 26 Tg 38 Td 30 sun	`[28.8, 'white']`	`[28.8, 'green']`	Failed
Tw 26 Tg 38 Td 30 indoor	`[29.6, 'white']`	`[29.6, 'yellow']`	Failed

SHA-256 / 540f5a678777adb80b1cbc3af810dca6e4b4b3a1ad6d59213278ff3058011577

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    w = round(w, 1)
    wf = w * 9 / 5 + 32
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']]], [['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']]], [['Tw 26 Tg 38 Td 30 sun', [26, 38, 30, True], [28.8, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']]], [['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 27 Tg 29.4 Td 30 sun', [27, 29.4, 30, True], [27.8, 'green']], ['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'white']`	`[22.5, 'white']`	Passed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'white']`	`[23.0, 'white']`	Passed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'green']`	`[26.8, 'green']`	Passed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'green']`	`[27.3, 'green']`	Passed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'green']`	`[28.6, 'green']`	Passed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'yellow']`	`[29.5, 'yellow']`	Passed
Tw 26 Tg 38 Td 30 sun	`[28.8, 'green']`	`[28.8, 'green']`	Passed
Tw 26 Tg 38 Td 30 indoor	`[29.6, 'yellow']`	`[29.6, 'yellow']`	Passed

SHA-256 / 145feafba73418b395e89b9077bf35fb78b08d8fc99bcab0948d8d51663a0aff

Verification & scope

Stipulated deterministic teaching model of an operational weather index; coefficients and thresholds are fixed by the contract and no claim of standards conformance is made. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:48:25.595699+00:00.

Case digest / 38c84704b099f47d62c04fe711f52349ff9a453f573337b1140ac6b62ad3bd95