Great South Run
Race Day Weather
Mild temps, strategic wind adjustments
Runners will face temperatures starting at 57°F and peaking at 59°F, with high humidity at 78%. A tailwind in miles 1-2 will aid early pacing, but a headwind in mile 6 requires a conservative approach. With wind gusts up to 26 mph, runners should anticipate crosswinds in miles 3-5 and 7-10, adjusting their lines accordingly. Hydration will be essential due to the humidity.
Pace Calculator
Enter a finish time to see what race day does to it.
Get forecast alerts for Great South Run
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Great South Run race plan
A mile-by-mile breakdown of where your time goes, weather-adjusted splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide, all built around your goal and race-day conditions.
Race Info
The Great South Run is an annual 10-mile road race in Portsmouth, England, first held in 1990. The flat, largely coastal course starts near Southsea Castle and finishes along the Southsea seafront, passing Portsmouth Historic Dockyard and the Spinnaker Tower. It hosts the UK Athletics 10-Mile Championships and draws over 20,000 finishers most years.
