A training target is not a weather obligation
A planned pace or distance does not become suitable merely because it appears on a schedule. The model does not know the effort of a particular session. An easy short loop and a long hard workout can have the same forecast inputs while presenting very different practical choices.
Look at the heat across the whole run and its return, not just at departure. Waiting for a lower air temperature alone can miss the role of humidity or direct sun. Keep apparent temperature, heat index and WBGT distinct; the explorer uses the model’s supplied feels-like value.
Use the score to inspect the reasons
The first heat deduction can leave an example in GO. That means only that the illustrated arithmetic has not crossed the app’s band. It does not demonstrate that a specific runner can tolerate the conditions. A warning, symptoms or a personal reason to avoid the heat can outweigh the colour.
Combining high feels-like temperature with wind, rain or another factor can reduce the score further. Conversely, favourable wind does not cancel a critical heat cap. Use a short nearby route when it offers a simpler exit, and avoid a plan that depends on completing a remote loop to get home.
Worked examples from the existing scorer
These complete hypothetical hours run through the same scoring functions used by the live tool. They are not observations or forecasts. The displayed effective score includes any cap.
| Example | Effective score | Verdict | Model reasons |
|---|---|---|---|
| Feels-like 25°C | 86/100 | GO | hot for running |
| Feels-like 29°C | 64/100 | MAYBE | very hot · MAYBE cap |
| Feels-like 33°C | 40/100 | NO-GO | dangerous heat · NOGO cap |
Exact example inputs and units
temp and feels: °C; wind and gust: km/h; precipitation: mm/h; visibility: m; rain probability, cloud and humidity: %. Weather code is WMO; UV is an index. Pressure, where shown, is context in hPa and does not affect this scorer.
[
{
"example": "Feels-like 25°C",
"inputs": {
"temp": 23,
"feels": 25,
"precip": 0,
"pop": 0,
"wind": 10,
"gust": 15,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Feels-like 29°C",
"inputs": {
"temp": 27,
"feels": 29,
"precip": 0,
"pop": 0,
"wind": 10,
"gust": 15,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Feels-like 33°C",
"inputs": {
"temp": 30,
"feels": 33,
"precip": 0,
"pop": 0,
"wind": 10,
"gust": 15,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
}
]Planning bands and the limits of the number
The existing model starts at 100, subtracts its condition penalties and applies critical caps. GO is 70–100, MAYBE 45–69 and NO-GO 0–44. A MAYBE cap limits the effective score to 64, and a NO-GO cap to 40. These are application suitability bands, not certified safe operating limits.
Rain branches are alternatives: matching probability, intensity and weather-code triggers do not mean adding the same rain penalty repeatedly. Separate factors can combine. A cap prevents benign temperature or dry weather from cancelling a critical flagged condition. Use the reasons beside the result to understand what changed.
The model requires complete numeric weather inputs. Missing visibility, rain probability or another required value returns Insufficient data; it is never filled with an invented favourable value. Local warnings, closures, equipment instructions and actual observations can change your decision even when the model returns GO.
Read the full running methodology and thresholds. The model and these examples were cross-checked on 18 October 2026. No physical field-test or safety certification is claimed.
Equipment and an alternative plan
Choose a cooler period, shorten the session or use an indoor alternative. Make breaks and access to a cooler place part of the plan. Follow official heat guidance rather than treating a drink, cap or forecast boundary as protection against all heat illness.
Questions about Too hot to run? Feels-like bands and changing the session
Is 24°C a medical limit?
No. It is the first feels-like deduction in this app’s running model.
Why does 29°C cap the result?
The current model caps feels-like above 28°C at MAYBE, even when other example conditions are benign.
Does the app prescribe a pace adjustment?
No. It does not model individual training or physiology.
Sources and limits
The numeric application bands come from the existing GoNoGo scorer and methodology. External guidance is linked for its stated context; it is not presented as endorsement of this model.
Live forecast data is supplied by Open-Meteo. An illustrative model output is different from a live forecast, and a forecast is different from a local observation.