Royal Parks Half weather.
Typically 11°C on race morning; rain in 1 of the last 10 years. Race morning (07:00 to 11:00 local time) in London on race day in each of the last 10 years; the 2027 race is on 10 Oct 2027.
- Typical
- 11°C (52°F)
- race-morning average
- Coolest
- 5°C (41°F)
- lowest reading, 07:00–11:00
- Warmest
- 21°C (70°F)
- highest reading, 07:00–11:00
- Wet years
- 1 of 10
- rain, drizzle or worse
- Humidity
- 80%
- typical
- Wind
- 9 km/h
- typical, at 10 m
Race morning, 07:00–11:00
Year by year
| Race day | Average | Low–high | Humidity | Wind | Rain | Conditions |
|---|---|---|---|---|---|---|
| 11 Oct 2026 | 11°C (51°F) | 8°C (47°F)–13°C (56°F) | 80% | 6 km/h | 0.0 mm | Partly cloudy |
| 12 Oct 2025 | 11°C (51°F) | 8°C (46°F)–14°C (56°F) | 91% | 4 km/h | 0.0 mm | Overcast |
| 13 Oct 2024 | 8°C (46°F) | 5°C (41°F)–10°C (51°F) | 74% | 10 km/h | 0.0 mm | Overcast |
| 8 Oct 2023 | 17°C (62°F) | 13°C (55°F)–21°C (70°F) | 79% | 6 km/h | 0.0 mm | Overcast |
| 9 Oct 2022 | 13°C (56°F) | 9°C (48°F)–16°C (62°F) | 71% | 16 km/h | 0.0 mm | Clear |
| 10 Oct 2021 | 14°C (58°F) | 11°C (53°F)–17°C (62°F) | 85% | 9 km/h | 0.1 mm | Overcast |
| 11 Oct 2020 | 10°C (50°F) | 7°C (45°F)–13°C (55°F) | 79% | 15 km/h | 0.0 mm | Clear |
| 13 Oct 2019 | 16°C (61°F) | 15°C (59°F)–17°C (62°F) | 86% | 27 km/h | 1.0 mm | Light drizzle |
| 7 Oct 2018 | 10°C (49°F) | 6°C (42°F)–13°C (55°F) | 69% | 14 km/h | 0.0 mm | Overcast |
| 8 Oct 2017 | 12°C (54°F) | 10°C (50°F)–14°C (57°F) | 85% | 8 km/h | 0.0 mm | Overcast |
Each row is the race's date that year where we know it, else the same weekday nearest its usual date. Temperatures and humidity are averaged over 07:00 to 11:00 local time, rain is the total over those hours, and conditions are the commonest over the morning. The half marathon starts at 09:00.
Kit and pacing
What it means
Good racing weather
Around 11°C is close to ideal for a fast time. Shorts and a vest are enough once you're moving; bring a throwaway layer for the wait in the start pen.
Have a warm-day plan
In the warmest of these years it reached 21°C by late morning. Decide in advance how much you'd slow down if the forecast is warm, rather than on the course.
The weather varies a lot
Race mornings here have ranged by 9°C from year to year. Pack for both, and settle your kit and pacing from the forecast in the last few days.
General guidance from past years' numbers. Check the forecast in race week.
Weather data by Open-Meteo.com, from its historical weather archive (CC BY 4.0).