The short answer
To get the weather along your running route, load the route as a GPX, FIT or TCX file into a tool that times the forecast to your pace. It works out when you'll reach each kilometre and reads the weather there. On one Seville half marathon morning, heat stress went from Low at the start to High by the finish.
Key takeaways
- A forecast for your town gives one place and one hour; a run covers many of both.
- Export your route as GPX, FIT or TCX from your watch app, mapping app or race website.
- Heat stress can climb faster than air temperature once the sun is up.
- On point-to-point runs, the finish can have a different climate from the start.
On this page
- How do you get the weather along your running route?
- Why does one forecast for your town miss the weather on your route?
- Where do you get a GPX, FIT or TCX file of your route?
- How is the forecast timed to your pace?
- What do other route weather tools do?
- What should you look for once you have the forecast?
- Questions runners ask
- Sources and method
Words this guide uses
- Pace-timed forecast
- The weather for each stretch of your route at the time you'll run it, from your start time and pace.
- GPX, FIT and TCX
- Common route and activity file formats: GPX is the open standard, FIT is Garmin's compact format, TCX is an older Garmin format.
How do you get the weather along your running route?
You get the weather along your running route by loading the route file into a tool that times the forecast to your pace. Give it a GPX, FIT or TCX file, your start time and your pace, and it reads the weather for each stretch at the hour you'll reach it.
That is a pace-timed forecast: the weather for each stretch of your route at the time you'll run it. Our running weather forecast hub explains why it beats a forecast for your town, and Map your run does it free in your browser.
Here is what it shows on a real summer morning. A runner starts a half marathon in Seville, Spain, at 07:00 on 10 July 2023, at 5:30 per km (8:51 per mile). These are the ERA5 reanalysis values at each marker, timed to their arrival.
| Marker, km (miles) | Clock time | Air, °C (°F) | Dew point, °C (°F) | WBGT, °C (°F) | Heat stress |
|---|---|---|---|---|---|
| Start | 07:00 | 21.8 (71) | 11.2 (52) | 16.9 (62) | Low |
| 5 (3.1) | 07:27 | 22.2 (72) | 11.5 (53) | 17.3 (63) | Low |
| 10 (6.2) | 07:55 | 22.5 (73) | 11.9 (53) | 19.2 (67) | Moderate |
| 15 (9.3) | 08:22 | 23.6 (75) | 11.9 (53) | 21.3 (70) | Moderate |
| 21.1 (13.1) | 08:56 | 25.2 (77) | 11.6 (53) | 23.6 (74) | High |
The air warmed only 3.4°C (6.1°F) in two hours. Heat stress rose 6.7°C (12.1°F), because the sun came up during the run. A forecast for 07:00 would have missed it.
Why does one forecast for your town miss the weather on your route?
Because a run covers distance and time, and the weather changes across both. A town forecast gives you one point and usually one hour.
Time is the bigger factor on most runs, as Seville shows. Distance matters on long point-to-point routes. The Comrades Marathon in South Africa runs about 90 km (56 miles) between Pietermaritzburg, inland at altitude, and Durban on the coast. On the 2023 down run, the organisers recorded 5/22°C (41/72°F) at Pietermaritzburg and 15/21°C (59/70°F) at Durban.
So the start was cold and the finish mild. RunFast's ERA5 race history puts the 9-hour runner's coldest feels like at 2.4°C (36°F) near the start. Heat stress reached Moderate from km 42. One forecast for either city would have been wrong for most of the day.
On a multi-day route, plan each day this way: see fastpacking weather.
Where do you get a GPX, FIT or TCX file of your route?
From the app you plan or record runs with, or from the race organiser. Almost every running watch app and mapping app can export one of these formats.
- A route you've run before: open the activity in your watch's app or your training log and export it. Garmin activities are stored as FIT files; most apps also offer GPX.
- A route you're planning: draw it in a route planner or mapping app and export it as GPX.
- A race: use the course file if the organiser publishes one. Check its distance against the official one first.
GPX is the safest choice, because almost every tool reads it. Make sure the file includes elevation.
How is the forecast timed to your pace?
The tool counts forward from your start time, kilometre by kilometre, at your pace. It adjusts each split for the gradient, then reads the forecast for that place at that minute.
The hill adjustment matters on rolling routes. Map your run uses the energy cost of running on slopes measured by Minetti and colleagues (2002), damped toward the grade-adjusted pace real runners hold. On a 5% climb that means about 17% slower than your flat pace. A long climb late in a run pushes every later marker back, and into warmer hours.
Enter the pace you'll actually run, not your best.
What do other route weather tools do?
Several tools forecast along a route, but as of September 2026 most are built for cyclists or hikers. They show speed rather than pace, and few show dew point or heat stress.
| Tool (as of September 2026) | What it does | Built for |
|---|---|---|
| Epic Ride Weather | Forecast along a route every 10 minutes: temperature, feels like, wind, rain | Cyclists |
| GPX Forecast | Drop a GPX, set pace and start; temperature, wind, rain by km; no account | Cyclists, hikers, trail runners |
| Route Forecast | Stretch-by-stretch wind, temperature and rain; best start time | Cyclists, with running supported |
| TrueEffort | Imports GPX, FIT, TCX or KML; grade-adjusted splits; route weather in its Pro tier | Runners (iPhone) |
For a run in the heat, look for dew point and WBGT at your pace, not just air temperature.
What should you look for once you have the forecast?
Look for the stretch where heat stress steps up a level, and when you reach it. That is where your plan needs to change.
Then check the exposed stretches, such as open roads, beaches and long climbs in full sun. Check the dew point near water, and the wind on the way home. A tailwind matched to your pace leaves you in still air, with no cooling breeze.
If the heat steps up late, start earlier. Our guide to the best time to run in hot weather has the numbers. If the problem is a headwind or a long climb, our guide to wind and hills explains what they cost.
Questions runners ask
Can I get a weather forecast for a route I've never run?
Yes. Draw the route in a mapping or route-planning app, or download the course from a race website where the organiser publishes one, then export it as a GPX file. The forecast tool only needs the line and the heights along it. It doesn't matter whether you've run it before, as long as the file follows the roads or trails you'll use.
Do route weather tools work for trail runs?
Yes, if your file includes elevation. Steep trails slow you far more than roads, so a tool that adjusts your split times for gradient will time the forecast better. Mountain weather can also differ sharply over short distances, so treat any forecast at a remote summit as a guide and carry kit for worse.
How far apart are the forecast points along my route?
It depends on the tool. Map your run cuts a route into stretches of about 1.5 km (0.9 miles) on a 10 km run or a marathon, and up to 5 km (3.1 miles) on very long routes, then reads the forecast at each. Cycling tools often use time steps instead, such as every 10 minutes along the ride.
Will the forecast follow me if I run slower than planned?
Not automatically, because a forecast tool can only time the weather to the pace you enter. Run the check twice: once at your goal pace and once a little slower. If the slower version pushes you into a higher heat-stress level near the end, plan for that version, because heat usually slows you further.
Is a GPX file of a marathon course the same as the official route?
Not always. Unofficial files drawn by runners can cut corners or miss a loop, which shifts your arrival times. Use the organiser's file where one is published, or check the distance and start point before you trust the timing. A difference of a kilometre moves your arrival by five to seven minutes at most paces.
See the heat at your pace.
Drop in your route (GPX, FIT or TCX), pick the day and your pace, and see the feels like, dew point and heat stress for every kilometre, timed to when you’ll be there. Free, in your browser, no sign-up.
Sources and method
- Comrades Marathon Association (2026). Histories (race-day temperatures at Pietermaritzburg and Durban)
- Journal of Applied Physiology (2002). Energy cost of walking and running at extreme uphill and downhill slopes (Minetti et al.)
- Journal of Occupational and Environmental Hygiene (2008). Modeling the wet bulb globe temperature using standard meteorological measurements (Liljegren et al.)
- Copernicus Climate Change Service (ECMWF) (2026). ERA5 hourly data on single levels from 1940 to present
- Open-Meteo (2026). Historical weather API (ERA5)
The Seville example uses hourly ERA5 reanalysis (Copernicus Climate Change Service, ECMWF) for 10 July 2023 at the grid point nearest the city (37.5°N, 6.0°W), fetched through Open-Meteo, interpolated to the minute each kilometre is reached at an even 5:30 per km (8:51 per mile) from a 07:00 start. WBGT uses the RunFast engine's Liljegren et al. (2008) model, with sunshine estimated from the sun's height and ERA5 cloud cover; dew point uses the Magnus formula. It is reanalysis at one grid point, not a thermometer reading, and it ignores shade from buildings and trees. Comrades figures are the organiser's published race-day minimum and maximum temperatures, plus RunFast's ERA5 race history for 11 June 2023 at a 9-hour finish. Imperial values are conversions.
Wes Thomson
Wes Thomson builds RunFast, which times the heat, humidity and dew point to a runner's own pace along the route, and its sister Windline, live wind forecasts for cyclists. Both run on the same forecast engine. He writes these guides with one focus: what the weather will do to your run, kilometre by kilometre, and how to plan around it.