Find the Best Time to Run, Anywhere on Earth
Most weather apps weren't built for runners. They tell you the high and low for the day — not when the heat becomes a problem, when the UV peaks, or which streets will be shaded at 7 in the morning. The I SPY SUN Runner Index answers those questions visually, for any town on the planet. Type a place name, and you'll see today's sun arc, the live conditions hour by hour, and a map showing exactly which direction sun and shadow are falling right now.
Why Sun Direction Matters for Runners
On a hot morning, a north-south street with east-facing buildings will be deeply shaded until mid-morning. The exact same street running east-west will be in full sun the entire time. Knowing where the sun sits in the sky — not just whether it's "out" or not — lets you pick routes that stay cool 5° cooler than the next street over. The Runner Index's map shows you the sun's bearing and the shadow's bearing for every minute of the day, so you can see at a glance which roads will be shaded when you actually want to run.
Live Conditions, Hour by Hour
The five tiles at the top of the page update as you scrub the slider: air temperature, the "feels like" reading (which accounts for humidity and wind), UV index, wind speed and direction, and relative humidity. The numbers come from Open-Meteo's hourly forecast for your exact location, in your local timezone. The sun arc and map use SunCalc and Leaflet to render the sun's real position at any minute of the day — not just a generic graph, but the actual angle and azimuth at that lat/lon.
Built for Holiday Runners and Daily Trainers
Whether you're visiting Limassol for a week, training for a marathon in Lisbon, or just wondering what time to head out tomorrow in your home town, the Runner Index gives you the answer in one screen. No app to download, no account to create, no paywall. Drag the slider, find the cool window, plan your route along the shaded streets — then go run.