Cape Town Marathon 2027 weather: what race day will likely feel like

The 2027 Sanlam Cape Town Marathon is on Sunday 23 May, the race's first year as an Abbott World Marathon Major: 42.2 km from Green Point through the city, out to Rondebosch, Newlands and Claremont, back through Observatory, Woodstock and the Company's Garden, and round the Sea Point Promenade to the finish on Vlei Road. Here's what race day has usually felt like, section by section, for a runner in the middle of the field.

What will the weather be like at the 2027 Cape Town Marathon?

Usually mild and humid, with a northerly breeze: fine for the first half, harder work in the second. In the records, a runner from an 08:27 start set off at about 13° and finished at about 17°, with a dew point near 13°. RunFast's engine rated race day Good on 2 days in 10, Fair on 7 and Tough on 1.

The heat stress (WBGT, the number race medical teams use) was usually about 18°. It reached Moderate or more on about 4 days in 10. The warmest race day in the records reached 23°.

Where does the weather usually cost runners time?

Both the wind and the heat, the wind more often. On the middle day of the records, the weather cost a 6:00-per-km runner about 6 minutes over the whole race, and 10 minutes or more on 1 day in 10. The wind was the main cause on about 6 of those days in 10.

Start and finish · Green PointRondeboschWoodstockSea Point1234567Historic

Green for the first 15 km, through the city and down the highway to Rondebosch and Newlands: on a middle day those stretches cost nothing. From Palmyra Road it turns amber, and from Rondebosch Common on it's mostly orange, hard: each stretch about 3 to 5% slower, as the morning warms, the air stays humid and the wind turns into runners' faces. Long Street and the run along Green Point Main Road stand out, at about 5%. The wind usually comes from the north at 13 to 15 km/h, so it's behind runners on the way out of the city to Rondebosch, and in their faces on the way back north, round Rondebosch Common, through Observatory, and down Long Street to Green Point.

What is each section likely to feel like?

Each section with its usual race morning, hour by hour, timed for an 08:27 start and a steady 6:00 per km. The course and times are 2026's; the organiser hasn't published 2027 changes yet.

1. Green Point and the city

From the start on Beach Road past the stadium and the city to the N2, where the organiser's spectator guide puts the Hyde Street off-ramp at 6.5 km. It was about 14°, with the northerly, about 13 km/h, more often behind runners than against them.

2. The highway to Rondebosch

Along the highway past Groote Schuur and down past the Baxter Theatre to Rondebosch. Still downwind: the northerly, about 13 km/h, was mostly behind runners on about 5 days in 10, and on the middle day the weather cost nothing here. It's about 15°, and the heat stress was Low on every day in the records.

3. Newlands, Claremont and Palmyra Road

Through Newlands and Claremont, then back up Palmyra Road to Rondebosch Park at 17.2 km. Out through Newlands and Claremont with the wind behind, then back up Palmyra Road into it. It's about 15° and humid, with a dew point near 12°, and this section was rated Good on 5 days in 10 and Fair on 5.

4. Rondebosch Common and Observatory

The loop round Rondebosch Common, with Devil's Peak behind it, past the Red Cross Children's Hospital and back through Observatory to Salt River Circle at 26.7 km. Heading north round the Common and back through Observatory, the wind, about 14 km/h, was mostly in runners' faces on about 5 days in 10. It's about 16°, the heat stress reached Moderate on about 2 days in 10, and this section was rated Good on only 3 days in 10.

5. Woodstock and the Castle

Albert Road through Woodstock, then Darling Street past the Castle of Good Hope, the Grand Parade and the City Hall at about 30 km. Mostly across the wind, about 15 km/h from the north. It's about 16°, and the heat stress reached Moderate on about 3 days in 10. This section was rated Good on only 2 days in 10.

6. The Company's Garden, Long Street and Green Point

The Company's Garden from 30.7 to 32.1 km is the longest and steepest climb of the day, says the organiser, and it's shaded. Then down Long Street and along Green Point Main Road to the Sea Point Promenade at 36.3 km. The hardest section. Down Long Street and along Green Point Main Road, the wind, about 14 km/h from the north-west, was mostly in runners' faces on about 5 days in 10. It's about 16°, and the heat stress reached Moderate on about 4 days in 10. This section was rated Tough on about 3 days in 10, the most of any.

7. The Sea Point Promenade loop

Out about 3 km along the ocean and back, then to the finish on Vlei Road. Out along the ocean and back, with the wind, about 15 km/h from the north-west, in runners' faces one way and behind them the other, so it about evens out. It's about 16° and humid, and the heat stress reached Moderate on about 4 days in 10, so this section was rated Fair on 8 days in 10.

What should runners wear and pack for race day?

Race kit for 13–17°, a layer for the wait, and a plan for wet weather. The organiser's marathon page and FAQ have the starts, the route, the cut-offs and the 15 hydration stations. From the weather records:

• A throwaway layer for the start. It was about 13° during the wait, 12° or colder on 1 morning in 10.
• Shorts and a light top for most runners. Expect about 13° at the start and 17° by a four-hour finish.
• A light shell or cap on wet days. Rain fell during the run on about 1 day in 10.
• A pacing plan for the Sea Point loop. The wind there is usually about 15 km/h from the north-west, in your face one way and behind you the other, and it's the warmest, most humid part of the race, so hold something back on the way out.

The marathon has a 6.5-hour cut-off, counted from the last runner over the start mat. South Africa has no daylight saving, so every time is South African Standard Time. Supporters at the finish can expect about 17° in the early afternoon.

When does the real forecast open?

Ten days before the race, in the RunFast app: on 13 May 2027. Load the course with your own pace and wave, and RunFast shows the heat and the wind at each stretch as you get there. From then on, trust the forecast over this preview.

How did we work this out?

The course was run again on every day from a week before to a week after 23 May, in each year from 2015 to 2024: 150 days. Each run started at 08:27, South African Standard Time, the 2026 time of the Beach Road blue wave, at a steady 6:00 per km, on that day's hourly Copernicus ERA5 weather, with its dew point and sunshine. RunFast's engine, the same one the app uses, worked out the heat stress and the weather's toll, and rated the run and each section. The start-area wait is the lowest temperature between 06:30 and the start, and a wet day has 1 mm of rain or more. Where ERA5's hourly temperature and dew point step every three hours (its weather stations there report every three hours), they're read at 00, 03, … 21 UTC and joined in straight lines, as Windline's route pages read them.

ERA5's grid cells are about 25 km across, and one covers this whole course, partly over the sea. Table Mountain's shelter, sea breezes and the city's own warmth don't show. The course line follows the streets on the organiser's 2026 route map and spectator guide, so it's close to the course but not the organiser's own file. Historic weather, not a forecast.

Sources: the Sanlam Cape Town Marathon's home page (22–23 May 2027, Abbott World Marathon Majors), FAQ (the marathon on 23 May 2027, the two starts, the finish on Vlei Road, the cut-off, the hydration stations), 2026 start and wave system and 2026 spectator guide (the start times, the course landmarks and their kilometres), and its route and landmarks map; ERA5 hourly time series (Hersbach et al., 2020). Course line drawn from © OpenStreetMap contributors. Contains modified Copernicus Climate Change Service information (2026). Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.