Conditions on this page are recalculated from the latest forecast every time it is opened, for the current date in the location's own time zone. Showing .
The best running temperature is lower than almost anyone expects. For easy running, 10 to 15 degrees Celsius is close to optimal. For hard efforts and racing it drops further, to between 7 and 12 degrees, and marathon performance data consistently shows finishing times degrading above about 13 degrees. The mechanism is heat dissipation: running generates roughly ten times the metabolic heat of standing, and once your body has to divert blood flow to the skin for cooling, less is available to the working muscles, so pace falls at identical effort. This is why a warm run feels harder without being faster. Dew point is the sharper predictor than relative humidity, because it captures how much evaporative cooling is available to you: below 13 degrees dew point is comfortable, 16 to 18 is noticeable, above 21 degrees is a genuine performance and safety limiter and the day to convert a tempo session into an easy run. Wind costs roughly two to four percent of pace into a sustained headwind and gives back less than half of that as a tailwind, which is why out-and-back routes on windy days are always net slower. Below freezing, the limiter is airway comfort and footing rather than performance. Use the thresholds here alongside a city running score to pick the hour of the day, which usually matters more than the day itself.
Scores are capped by dealbreakers — heavy rain, dangerous wind, thick fog or hazardous UV pull a day down no matter how pleasant the rest of the numbers look. Forecast data is Open-Meteo; solar and lunar values are computed for this location's own coordinates and time zone. Full details on the methodology page.