RunWeather data study · updated 27 Oct 2026
Marathon race-morning weather, 2021 to 2026
What the nearest airport or official weather station measured at the first-wave start of 62 marathons, on the day each race was held: 291 race mornings in all.
Hottest start27°C81°F
Singapore, 4:30 a.m., in 2022 and 2023. Dew point 22 to 24°C.
Most humid start24.5°Cdew 76°F
Kuala Lumpur, 3:30 a.m., 6 Oct 2024. Air 25.5°C.
Biggest swing between years18°C33°F
Indianapolis Monumental Marathon: −1.6°C at the 2021 start, 16.6°C in 2022.
Typical same-effort cost, 4:00 runner2 minmedian
On half of the priced mornings the pace model put it at 2 minutes or less. Hadley’s temperature plus dew point rule of thumb priced 0.
Every race morning
Start temperature and dew point at the first-wave clock, hottest first. The cost columns are the extra minutes a 4:00 marathoner would need at the same effort: our pace model, then Hadley’s temperature plus dew point rule of thumb (see Method).
| Race | Start °C | Dew °C | 4:00 cost | Hadley |
|---|---|---|---|---|
| Singapore International Marathon2022 · 4:30 a.m. | 27 | 22 | +38 | +13 |
| Singapore International Marathon2023 · 4:30 a.m. | 27 | 24 | +46 | +13 |
| Singapore International Marathon2025 · 4:30 a.m. | 26.5 | 22 | +38 | +13 |
| Kuala Lumpur Marathon2023 · 3:30 a.m. | 26 | 24 | +46 | +13 |
| Kuala Lumpur Marathon2025 · 3:30 a.m. | 26 | 24 | +46 | +13 |
| Singapore International Marathon2024 · 4:30 a.m. | 26 | 24 | +46 | +13 |
| Kuala Lumpur Marathon2024 · 3:30 a.m. | 25.5 | 24.5 | +48 | +13 |
| Kuala Lumpur Marathon2022 · 3:30 a.m. | 25 | 24 | +43 | +13 |
| Kuala Lumpur Marathon2026 · 3:30 a.m. | 25 | 23 | +41 | +13 |
| Honolulu Marathon2022 · 5:00 a.m. | 24 | 18.3 | +24 | +9 |
| Miami Marathon2023 · 5:55 a.m. | 23.9 | 18.3 | +22 | +6 |
| Honolulu Marathon2025 · 5:00 a.m. | 23.3 | 21.8 | +29 | +9 |
| Miami Marathon2026 · 5:55 a.m. | 23.3 | 20.6 | +24 | +9 |
| Abu Dhabi Marathon2021 · 5:55 a.m. | 23 | 18.9 | +24 | +6 |
| Honolulu Marathon2021 · 5:00 a.m. | 22.8 | 19.4 | +22 | +6 |
| Miami Marathon2024 · 5:55 a.m. | 22.8 | 21.7 | +26 | +9 |
| Chicago Marathon2021 · 7:35 a.m. | 22.4 | 16.1 | +17 | +6 |
| Honolulu Marathon2024 · 5:00 a.m. | 22.2 | 19.4 | +22 | +6 |
| Miami Marathon2025 · 5:55 a.m. | 22.2 | 21.7 | +26 | +9 |
| Abu Dhabi Marathon2025 · 5:55 a.m. | 22 | 12 | +17 | +4 |
| New York City Marathon2022 · 9:10 a.m. | 21.9 | 17 | +17 | +6 |
| Honolulu Marathon2023 · 5:00 a.m. | 21.5 | 19.9 | +19 | +6 |
| Abu Dhabi Marathon2022 · 5:55 a.m. | 21 | 17.9 | +17 | +6 |
| Abu Dhabi Marathon2023 · 5:55 a.m. | 21 | 13 | +14 | +4 |
| Twin Cities Marathon2025 · 8:00 a.m. | 20.7 | 12.8 | +17 | +4 |
| Yokohama Marathon2024 · 8:30 a.m. | 20.5 | 17 | +22 | +6 |
| Hong Kong Marathon2023 · 6:00 a.m. | 20 | 18 | +14 | +6 |
| Hong Kong Marathon2026 · 6:00 a.m. | 20 | 7 | +10 | +2 |
| Kobe Marathon2024 · 9:00 a.m. | 20 | 16 | +19 | +4 |
| Lisbon Marathon2024 · 8:00 a.m. | 20 | 19 | +14 | +6 |
| Miami Marathon2022 · 5:55 a.m. | 19.4 | 18.9 | +14 | +6 |
| Toronto Waterfront Marathon2025 · 8:00 a.m. | 19.4 | 13 | +12 | +4 |
| Marine Corps Marathon2023 · 7:20 a.m. | 19.2 | 16.7 | +12 | +4 |
| Abu Dhabi Marathon2024 · 5:55 a.m. | 19.1 | 14.1 | +12 | +4 |
| Hong Kong Marathon2021 · 6:00 a.m. | 19 | 15 | +12 | +4 |
| Lisbon Marathon2023 · 8:00 a.m. | 19 | 16 | +19 | +4 |
| Lisbon Marathon2025 · 8:00 a.m. | 19 | 19 | +12 | +6 |
| Berlin Marathon2025 · 8:45 a.m. | 18.9 | 15 | +17 | +4 |
| Sydney Marathon2023 · 6:30 a.m. | 18.5 | 5.5 | +12 | +1 |
| Vienna City Marathon2021 · 9:00 a.m. | 18.5 | 15 | +17 | +4 |
| Dubai Marathon2024 · 5:45 a.m. | 18.3 | 13 | +10 | +4 |
| Dubai Marathon2023 · 5:45 a.m. | 18 | 14 | +10 | +4 |
| Lisbon Marathon2021 · 8:00 a.m. | 18 | 18 | +10 | +4 |
| Boston Marathon2021 · 10:00 a.m. | 17.9 | 15.1 | +10 | +4 |
| Dubai Marathon2025 · 5:45 a.m. | 17.3 | 5 | +5 | +1 |
| Los Angeles Marathon2023 · 7:00 a.m. | 17.3 | 4.3 | +5 | +1 |
| Málaga Marathon2022 · 8:30 a.m. | 17 | 14.5 | +7 | +4 |
| Marathon des Alpes-Maritimes Nice-Cannes2022 · 8:00 a.m. | 17 | 6 | +5 | +1 |
| Marathon Hamburg2021 · 8:30 a.m. | 17 | 16 | +7 | +4 |
| Perth Running Festival Marathon2021 · 6:00 a.m. | 17 | 10 | +10 | +2 |
| Venice Marathon2024 · 9:40 a.m. | 17 | 16 | +7 | +4 |
| Walt Disney World Marathon2026 · 4:30 a.m. | 16.7 | 15.6 | +7 | +4 |
| Indianapolis Monumental Marathon2022 · 8:00 a.m. | 16.6 | 11.8 | +7 | +2 |
| Dubai Marathon2026 · 5:45 a.m. | 16.3 | 12.3 | +7 | +2 |
| Frankfurt Marathon2022 · 10:00 a.m. | 16.3 | 13.8 | +10 | +2 |
| Walt Disney World Marathon2024 · 4:30 a.m. | 16.1 | 14.7 | +7 | +2 |
| Cologne Marathon2023 · 10:30 a.m. | 16 | 11.7 | +10 | +2 |
| Hong Kong Marathon2024 · 6:00 a.m. | 16 | 8 | +5 | +1 |
| Lisbon Marathon2022 · 8:00 a.m. | 16 | 14 | +7 | +2 |
| Lisbon Marathon2026 · 8:00 a.m. | 16 | 10 | +7 | +2 |
| Marató de Barcelona2022 · 8:30 a.m. | 16 | 7.5 | +10 | +1 |
| Porto Marathon2024 · 8:00 a.m. | 16 | 12 | +10 | +2 |
| Berlin Marathon2021 · 8:45 a.m. | 15.8 | 14.9 | +10 | +2 |
| Chicago Marathon2024 · 7:35 a.m. | 15.8 | 11.5 | +7 | +2 |
| Athens Marathon2023 · 8:30 a.m. | 15.7 | 10.7 | +10 | +2 |
| Chicago Marathon2026 · 7:35 a.m. | 15.6 | 11.7 | +5 | +2 |
| Yokohama Marathon2022 · 8:30 a.m. | 15.5 | 6 | +5 | +1 |
| Marathon Bonn2023 · 11:00 a.m. | 15.3 | 9.8 | +5 | +1 |
| Marathon Bonn2024 · 11:00 a.m. | 15.2 | 9 | +5 | +1 |
| Bucharest Marathon2026 · 9:00 a.m. | 15 | 12 | +7 | +2 |
| Houston Marathon2023 · 6:55 a.m. | 15 | 12 | +5 | +2 |
| Kobe Marathon2022 · 9:00 a.m. | 15 | 11 | +5 | +2 |
| Marathon Vert de Rennes2022 · 9:00 a.m. | 15 | 13 | +7 | +2 |
| Prague Marathon2026 · 8:00 a.m. | 15 | 4 | +2 | +0 |
| Warsaw Marathon2021 · 9:00 a.m. | 15 | 14 | +7 | +2 |
| Yokohama Marathon2023 · 8:30 a.m. | 15 | 10 | +7 | +1 |
| Yokohama Marathon2025 · 8:30 a.m. | 15 | 15 | +5 | +2 |
| London Marathon2022 · 9:35 a.m. | 14.8 | 12 | +5 | +2 |
| Shanghai Marathon2022 · 6:45 a.m. | 14.8 | 13.8 | +5 | +2 |
| Boston Marathon2024 · 10:00 a.m. | 14.7 | 7.8 | +7 | +1 |
| Venice Marathon2023 · 9:40 a.m. | 14.7 | 13.7 | +7 | +2 |
| Taipei Marathon2021 · 6:30 a.m. | 14.5 | 9 | +5 | +1 |
| Cologne Marathon2026 · 10:30 a.m. | 14.3 | 11 | +5 | +1 |
| Vienna City Marathon2023 · 9:00 a.m. | 14.3 | 7.2 | +2 | +1 |
| Vienna City Marathon2026 · 9:00 a.m. | 14.3 | 5.8 | +2 | +1 |
| Amsterdam Marathon2024 · 9:00 a.m. | 14 | 13 | +5 | +2 |
| Austin Marathon2026 · 7:00 a.m. | 14 | 11.2 | +5 | +1 |
| Cologne Marathon2022 · 10:30 a.m. | 14 | 11.3 | +5 | +1 |
| Frankfurt Marathon2023 · 10:00 a.m. | 14 | 12 | +5 | +2 |
| Kobe Marathon2025 · 9:00 a.m. | 14 | 7 | +5 | +1 |
| Marathon des Alpes-Maritimes Nice-Cannes2024 · 8:00 a.m. | 14 | 8 | +5 | +1 |
| Melbourne Marathon2026 · 6:15 a.m. | 14 | 9 | +5 | +1 |
| Osaka Marathon2026 · 9:15 a.m. | 14 | 4.5 | +5 | +0 |
| Perth Running Festival Marathon2024 · 6:00 a.m. | 14 | 13 | +5 | +2 |
| Porto Marathon2022 · 8:00 a.m. | 14 | 13 | +5 | +2 |
| Porto Marathon2023 · 8:00 a.m. | 14 | 10 | +5 | +1 |
| Prague Marathon2024 · 8:00 a.m. | 14 | 11 | +5 | +1 |
| Seville Marathon2023 · 8:29 a.m. | 14 | 7 | +2 | +1 |
| Taipei Marathon2024 · 6:30 a.m. | 14 | 9 | +2 | +1 |
| Twin Cities Marathon2021 · 8:00 a.m. | 14 | 12.2 | +7 | +2 |
| Vienna City Marathon2022 · 9:00 a.m. | 14 | 8 | +5 | +1 |
| Warsaw Marathon2023 · 9:00 a.m. | 14 | 12 | +5 | +2 |
| Athens Marathon2021 · 8:30 a.m. | 13.7 | 9.7 | +5 | +1 |
| New York City Marathon2023 · 9:10 a.m. | 13.5 | 5.4 | +0 | +0 |
| Venice Marathon2025 · 9:40 a.m. | 13.5 | 9.2 | +5 | +1 |
| Twin Cities Marathon2022 · 8:00 a.m. | 13.4 | 11 | +5 | +1 |
| Athens Marathon2024 · 8:30 a.m. | 13.3 | 6 | +2 | +0 |
| Chester Marathon2023 · 9:00 a.m. | 13.3 | 10.2 | +2 | +1 |
| Los Angeles Marathon2021 · 7:00 a.m. | 13.3 | 11.1 | +5 | +1 |
| Rome Marathon2025 · 8:30 a.m. | 13.3 | 8.3 | +5 | +1 |
| Tokyo Marathon2026 · 9:10 a.m. | 13.3 | -4.2 | +0 | +0 |
| Chester Marathon2022 · 9:00 a.m. | 13.2 | 9.2 | +5 | +1 |
| Edinburgh Marathon2025 · 10:00 a.m. | 13.2 | 7.8 | +10 | +1 |
| Amsterdam Marathon2022 · 9:00 a.m. | 13.1 | 12 | +7 | +1 |
| Marathon Rotterdam2025 · 10:00 a.m. | 13.1 | 9.1 | +5 | +1 |
| Bucharest Marathon2023 · 9:00 a.m. | 13 | 9 | +5 | +1 |
| Frankfurt Marathon2024 · 10:00 a.m. | 13 | 11 | +2 | +1 |
| Kobe Marathon2023 · 9:00 a.m. | 13 | 4 | +2 | +0 |
| Málaga Marathon2023 · 8:30 a.m. | 13 | 9 | +2 | +1 |
| Milano Marathon2026 · 8:15 a.m. | 13 | 9 | +2 | +1 |
| Perth Running Festival Marathon2026 · 6:00 a.m. | 13 | 12 | +2 | +1 |
| San Sebastián Marathon2025 · 9:00 a.m. | 13 | 9 | +2 | +1 |
| Sydney Marathon2022 · 6:30 a.m. | 13 | 6 | +2 | +0 |
| Taipei Marathon2023 · 6:30 a.m. | 13 | 9 | +2 | +1 |
| Warsaw Marathon2026 · 9:00 a.m. | 13 | 11 | +5 | +1 |
| Berlin Marathon2023 · 8:45 a.m. | 12.9 | 10.9 | +2 | +1 |
| Berlin Marathon2026 · 8:45 a.m. | 12.9 | 9 | +5 | +1 |
| Dublin Marathon2022 · 8:45 a.m. | 12.8 | 8 | +5 | +1 |
| London Marathon2026 · 9:35 a.m. | 12.8 | 7.3 | +0 | +1 |
| Milano Marathon2025 · 8:15 a.m. | 12.8 | 7.4 | +5 | +1 |
| Los Angeles Marathon2022 · 7:00 a.m. | 12.7 | 5.3 | +0 | +0 |
| Marathon Hamburg2024 · 8:30 a.m. | 12.7 | 7 | +2 | +0 |
| London Marathon2025 · 9:35 a.m. | 12.5 | 9 | +5 | +1 |
| Marató de Barcelona2023 · 8:30 a.m. | 12.5 | 10 | +2 | +1 |
| Boston Marathon2025 · 10:00 a.m. | 12.4 | -6.8 | +0 | +0 |
| Athens Marathon2022 · 8:30 a.m. | 12.3 | 9.3 | +2 | +1 |
| Chester Marathon2025 · 9:00 a.m. | 12.2 | 7.2 | +5 | +0 |
| Marathon Hannover2024 · 10:00 a.m. | 12.2 | 4 | +2 | +0 |
| Bucharest Marathon2022 · 9:00 a.m. | 12 | 9 | +2 | +1 |
| Bucharest Marathon2024 · 9:00 a.m. | 12 | 8 | +0 | +0 |
| Edinburgh Marathon2024 · 10:00 a.m. | 12 | 11.2 | +2 | +1 |
| Hong Kong Marathon2025 · 6:00 a.m. | 12 | -5 | +0 | +0 |
| Ljubljana Marathon2023 · 9:00 a.m. | 12 | 11 | +2 | +1 |
| London Marathon2023 · 9:35 a.m. | 12 | 7.8 | +0 | +0 |
| Málaga Marathon2025 · 8:30 a.m. | 12 | 11.5 | +2 | +1 |
| Marathon Bonn2026 · 11:00 a.m. | 12 | 6.8 | +2 | +0 |
| Marathon Rotterdam2024 · 10:00 a.m. | 12 | 5 | +0 | +0 |
| Porto Marathon2025 · 8:00 a.m. | 12 | 11 | +2 | +1 |
| Prague Marathon2022 · 8:00 a.m. | 12 | 8 | +2 | +0 |
| Berlin Marathon2022 · 8:45 a.m. | 11.9 | 8 | +0 | +0 |
| Walt Disney World Marathon2023 · 4:30 a.m. | 11.9 | 10.3 | +2 | +1 |
| London Marathon2021 · 9:35 a.m. | 11.8 | 8.3 | +0 | +1 |
| Los Angeles Marathon2024 · 7:00 a.m. | 11.8 | 7.8 | +0 | +0 |
| Milano Marathon2024 · 8:15 a.m. | 11.8 | 9.8 | +2 | +1 |
| Valencia Marathon2021 · 8:15 a.m. | 11.8 | 1 | +5 | +0 |
| Valencia Marathon2025 · 8:15 a.m. | 11.8 | 9.3 | +2 | +1 |
| Cologne Marathon2025 · 10:30 a.m. | 11.7 | 7.3 | +2 | +0 |
| Rome Marathon2023 · 8:30 a.m. | 11.7 | 9.7 | +0 | +1 |
| Tokyo Marathon2025 · 9:10 a.m. | 11.5 | 4.2 | +0 | +0 |
| Chester Marathon2024 · 9:00 a.m. | 11.3 | 10.2 | +2 | +1 |
| Maratona di Ravenna Città d’Arte2021 · 9:15 a.m. | 11.3 | 11 | +2 | +1 |
| Twin Cities Marathon2024 · 8:00 a.m. | 11.2 | 2.3 | +2 | +0 |
| Dallas Marathon2022 · 8:00 a.m. | 11.1 | 10 | +0 | +1 |
| Amsterdam Marathon2021 · 9:00 a.m. | 11 | 7 | +2 | +0 |
| Bucharest Marathon2025 · 9:00 a.m. | 11 | 8 | +0 | +0 |
| Ljubljana Marathon2024 · 9:00 a.m. | 11 | 8 | +0 | +0 |
| Prague Marathon2025 · 8:00 a.m. | 11 | 6 | +0 | +0 |
| Seville Marathon2022 · 8:29 a.m. | 11 | 7.5 | +0 | +0 |
| Sydney Marathon2026 · 6:30 a.m. | 11 | 9 | +0 | +0 |
| Chicago Marathon2025 · 7:35 a.m. | 10.9 | 8.2 | +0 | +0 |
| Boston Marathon2023 · 10:00 a.m. | 10.7 | 9 | +0 | +0 |
| Florence Marathon2022 · 8:30 a.m. | 10.7 | 4.7 | +0 | +0 |
| Milano Marathon2023 · 8:15 a.m. | 10.4 | 6.4 | +0 | +0 |
| Chester Marathon2026 · 9:00 a.m. | 10.3 | 6.2 | +0 | +0 |
| Twin Cities Marathon2026 · 8:00 a.m. | 10.3 | 7.2 | +0 | +0 |
| Boston Marathon2022 · 10:00 a.m. | 10.2 | -3.5 | +0 | +0 |
| California International Marathon2023 · 7:00 a.m. | 10.2 | 9.1 | +0 | +0 |
| Edinburgh Marathon2022 · 10:00 a.m. | 10.2 | 3 | +0 | +0 |
| Marathon Rotterdam2026 · 10:00 a.m. | 10.1 | 5.1 | +2 | +0 |
| Amsterdam Marathon2026 · 9:00 a.m. | 10 | 9 | +2 | +0 |
| Bucharest Marathon2021 · 9:00 a.m. | 10 | 7 | +0 | +0 |
| Ljubljana Marathon2022 · 9:00 a.m. | 10 | 10 | +0 | +0 |
| Marathon des Alpes-Maritimes Nice-Cannes2025 · 8:00 a.m. | 10 | 6 | +0 | +0 |
| Maratona di Ravenna Città d’Arte2022 · 9:15 a.m. | 10 | 8 | +0 | +0 |
| Melbourne Marathon2023 · 6:15 a.m. | 10 | 8 | +0 | +0 |
| Prague Marathon2023 · 8:00 a.m. | 10 | 6 | +0 | +0 |
| Warsaw Marathon2022 · 9:00 a.m. | 10 | 6 | +0 | +0 |
| Shanghai Marathon2023 · 6:45 a.m. | 9.8 | 6.8 | +0 | +0 |
| Marathon Hamburg2023 · 8:30 a.m. | 9.7 | 7.3 | +0 | +0 |
| New York City Marathon2025 · 9:10 a.m. | 9.6 | 1.3 | +0 | +0 |
| Austin Marathon2023 · 7:00 a.m. | 9.5 | 9 | +0 | +0 |
| Málaga Marathon2021 · 8:30 a.m. | 9.5 | 6.5 | +0 | +0 |
| Marató de Barcelona2024 · 8:30 a.m. | 9.5 | 3 | +0 | +0 |
| Marató de Barcelona2026 · 8:30 a.m. | 9.5 | 0 | +2 | +0 |
| Valencia Marathon2024 · 8:15 a.m. | 9.5 | 9.3 | +0 | +0 |
| Cologne Marathon2024 · 10:30 a.m. | 9.3 | 6.7 | +2 | +0 |
| Melbourne Marathon2025 · 6:15 a.m. | 9.3 | 6 | +0 | +0 |
| Rome Marathon2024 · 8:30 a.m. | 9.3 | 9.3 | +0 | +0 |
| Rome Marathon2026 · 8:30 a.m. | 9.3 | 6.3 | +0 | +0 |
| Chester Marathon2021 · 9:00 a.m. | 9.2 | 7.2 | +2 | +0 |
| Marathon Hannover2026 · 10:00 a.m. | 9.2 | 6 | +0 | +0 |
| Marathon Vert de Rennes2025 · 9:00 a.m. | 9 | 7 | +0 | +0 |
| San Sebastián Marathon2021 · 9:00 a.m. | 9 | 4 | +5 | +0 |
| Seville Marathon2024 · 8:29 a.m. | 9 | 7.5 | +0 | +0 |
| Taipei Marathon2022 · 6:30 a.m. | 9 | 0 | +2 | +0 |
| Tokyo Marathon2023 · 9:10 a.m. | 9 | -1 | +2 | +0 |
| Valencia Marathon2022 · 8:15 a.m. | 9 | 6.3 | +0 | +0 |
| Warsaw Marathon2025 · 9:00 a.m. | 9 | 6 | +0 | +0 |
| Philadelphia Marathon2024 · 7:00 a.m. | 8.9 | 2.2 | +2 | +0 |
| Toronto Waterfront Marathon2024 · 8:00 a.m. | 8.9 | 6.4 | +0 | +0 |
| Shanghai Marathon2025 · 6:45 a.m. | 8.8 | 7.8 | +0 | +0 |
| Marathon Hamburg2022 · 8:30 a.m. | 8.7 | 4 | +2 | +0 |
| Marine Corps Marathon2024 · 7:20 a.m. | 8.6 | 1.1 | +0 | +0 |
| Melbourne Marathon2021 · 6:15 a.m. | 8.5 | 7.5 | +0 | +0 |
| Sydney Marathon2024 · 6:30 a.m. | 8.5 | 1.5 | +2 | +0 |
| Sydney Marathon2025 · 6:30 a.m. | 8.5 | 2 | +0 | +0 |
| Florence Marathon2021 · 8:30 a.m. | 8.3 | 5 | +0 | +0 |
| Marathon Hamburg2025 · 8:30 a.m. | 8.3 | 1 | +0 | +0 |
| Tokyo Marathon2022 · 9:10 a.m. | 8.3 | -12 | +5 | +0 |
| Chicago Marathon2022 · 7:35 a.m. | 8.2 | -0.2 | +5 | +0 |
| Chicago Marathon2023 · 7:35 a.m. | 8.2 | 2.6 | +2 | +0 |
| Toronto Waterfront Marathon2022 · 8:00 a.m. | 8.2 | 2 | +0 | +0 |
| Indianapolis Monumental Marathon2024 · 8:00 a.m. | 8.1 | 4.5 | +0 | +0 |
| Marathon Rotterdam2021 · 10:00 a.m. | 8.1 | 5 | +0 | +0 |
| Marathon Rotterdam2022 · 10:00 a.m. | 8.1 | 1 | +2 | +0 |
| Marathon Rotterdam2023 · 10:00 a.m. | 8.1 | 8 | +2 | +0 |
| Toronto Waterfront Marathon2023 · 8:00 a.m. | 8.1 | 3.9 | +2 | +0 |
| Amsterdam Marathon2023 · 9:00 a.m. | 8 | 5.1 | +2 | +0 |
| Amsterdam Marathon2025 · 9:00 a.m. | 8 | 5 | +2 | +0 |
| California International Marathon2021 · 7:00 a.m. | 8 | 8 | +0 | +0 |
| California International Marathon2022 · 7:00 a.m. | 8 | 7 | +0 | +0 |
| Frankfurt Marathon2025 · 10:00 a.m. | 8 | 1.8 | +7 | +0 |
| Ljubljana Marathon2025 · 9:00 a.m. | 8 | 5 | +0 | +0 |
| Marathon Hannover2023 · 10:00 a.m. | 8 | 5 | +0 | +0 |
| Marathon Vert de Rennes2024 · 9:00 a.m. | 8 | 8 | +0 | +0 |
| Marathon Vert de Rennes2026 · 9:00 a.m. | 8 | 7 | +0 | +0 |
| Maratona di Ravenna Città d’Arte2024 · 9:15 a.m. | 8 | 8 | +0 | +0 |
| Perth Running Festival Marathon2025 · 6:00 a.m. | 8 | 7 | +0 | +0 |
| Seville Marathon2025 · 8:29 a.m. | 8 | 7.5 | +0 | +0 |
| Shanghai Marathon2024 · 6:45 a.m. | 8 | 4.3 | +0 | +0 |
| Boston Marathon2026 · 10:00 a.m. | 7.9 | -2.2 | +2 | +0 |
| London Marathon2024 · 9:35 a.m. | 7.8 | 0.3 | +5 | +0 |
| New York City Marathon2021 · 9:10 a.m. | 7.7 | 1.2 | +0 | +0 |
| Marató de Barcelona2021 · 8:30 a.m. | 7.5 | 0 | +0 | +0 |
| Marathon Bonn2025 · 11:00 a.m. | 7.3 | -8 | +5 | +0 |
| Marathon Hamburg2026 · 8:30 a.m. | 7.3 | 3 | +0 | +0 |
| California International Marathon2025 · 7:00 a.m. | 7 | 6 | +0 | +0 |
| Ljubljana Marathon2026 · 9:00 a.m. | 7 | 7 | +0 | +0 |
| Osaka Marathon2024 · 9:15 a.m. | 7 | 5 | +0 | +0 |
| San Sebastián Marathon2022 · 9:00 a.m. | 7 | 5 | +5 | +0 |
| Warsaw Marathon2024 · 9:00 a.m. | 7 | 6 | +2 | +0 |
| Berlin Marathon2024 · 8:45 a.m. | 6.8 | 5.8 | +0 | +0 |
| Dublin Marathon2024 · 8:45 a.m. | 6.8 | 4.8 | +0 | +0 |
| Dublin Marathon2025 · 8:45 a.m. | 6.8 | 4.8 | +2 | +0 |
| New York City Marathon2024 · 9:10 a.m. | 6.6 | -3.5 | +5 | +0 |
| Málaga Marathon2024 · 8:30 a.m. | 6.5 | 6 | +0 | +0 |
| Seville Marathon2026 · 8:29 a.m. | 6.5 | 5.5 | +0 | +0 |
| Marine Corps Marathon2025 · 7:20 a.m. | 6.4 | 4.2 | +0 | +0 |
| Florence Marathon2024 · 8:30 a.m. | 6.3 | 2.3 | +2 | +0 |
| Tokyo Marathon2024 · 9:10 a.m. | 6.3 | -9.7 | +5 | +0 |
| Houston Marathon2026 · 6:55 a.m. | 6 | -4 | +5 | +0 |
| Ljubljana Marathon2021 · 9:00 a.m. | 6 | 5 | +0 | +0 |
| Marathon des Alpes-Maritimes Nice-Cannes2021 · 8:00 a.m. | 6 | -5 | +5 | +0 |
| Marató de Barcelona2025 · 8:30 a.m. | 6 | 1 | +2 | +0 |
| Dublin Marathon2023 · 8:45 a.m. | 5.3 | 4.3 | +2 | +0 |
| Indianapolis Monumental Marathon2025 · 8:00 a.m. | 5.3 | 3.5 | +2 | +0 |
| Marathon Hannover2025 · 10:00 a.m. | 5.2 | -5.8 | +5 | +0 |
| Vienna City Marathon2024 · 9:00 a.m. | 5.2 | -0.2 | +7 | +0 |
| Houston Marathon2024 · 6:55 a.m. | 5 | -1 | +5 | +0 |
| Marathon Vert de Rennes2021 · 9:00 a.m. | 5 | 4 | +2 | +0 |
| Marine Corps Marathon2022 · 7:20 a.m. | 5 | 3.1 | +2 | +0 |
| Porto Marathon2021 · 8:00 a.m. | 5 | 3 | +2 | +0 |
| Valencia Marathon2023 · 8:15 a.m. | 5 | 1 | +5 | +0 |
| Toronto Waterfront Marathon2026 · 8:00 a.m. | 4.8 | 1.7 | +5 | +0 |
| Philadelphia Marathon2021 · 7:00 a.m. | 4.4 | 2.3 | +5 | +0 |
| Milano Marathon2022 · 8:15 a.m. | 4.3 | 2.4 | +5 | +0 |
| California International Marathon2024 · 7:00 a.m. | 4 | 4 | +2 | +0 |
| San Sebastián Marathon2023 · 9:00 a.m. | 4 | 4 | +2 | +0 |
| Osaka Marathon2023 · 9:15 a.m. | 3.5 | -2.3 | +10 | +0 |
| Marathon Hannover2022 · 10:00 a.m. | 3.2 | -2 | +10 | +0 |
| Osaka Marathon2025 · 9:15 a.m. | 3 | -3.3 | +10 | +0 |
| Philadelphia Marathon2025 · 7:00 a.m. | 2.4 | -1.4 | +7 | +0 |
| Austin Marathon2025 · 7:00 a.m. | 2.2 | -3.3 | +12 | +0 |
| Houston Marathon2022 · 6:55 a.m. | 1 | -4 | +12 | +0 |
| Vienna City Marathon2025 · 9:00 a.m. | 1 | -9 | +19 | +0 |
| Austin Marathon2024 · 7:00 a.m. | 0.8 | -5 | +12 | +0 |
| Houston Marathon2025 · 6:55 a.m. | 0 | -8 | +17 | +0 |
| Florence Marathon2025 · 8:30 a.m. | -0.7 | -1.3 | +12 | +0 |
| Dallas Marathon2025 · 8:00 a.m. | -1.1 | -7.2 | +19 | +0 |
| Florence Marathon2023 · 8:30 a.m. | -1.3 | -3.7 | +12 | +0 |
| Indianapolis Monumental Marathon2021 · 8:00 a.m. | -1.6 | -3.2 | +12 | +0 |
Method
Temperature and dew point come from the METAR reports of the nearest airport or official weather station (Iowa Environmental Mesonet archive), interpolated to each race’s first-wave clock on the date it was held. The same clock is used every year. Held dates come from World Athletics and AIMS results, or from the organiser for races already run in 2026. The CSV names each station and its distance from the start. Free to reuse under CC BY 4.0: credit RunWeather and link to this page.
The 4:00 cost uses the same pace model as the Run Score and every RunWeather race guide, with sun and wind from the ERA5 reanalysis, since stations do not measure sunshine. Hadley’s rule sits beside it so you can check the size by hand: add the temperature and dew point in °F, and every 10 points above 100 adds to the slowdown.
Checks: Berlin and Hamburg mornings match Germany’s weather service (DWD) within 1.2°C air and 0.8°C dew point on all 12. The ERA5 grid misses the station by more than 3°F air or 4°F dew point on 81 of 291 mornings, which is why the station is the number shown.
Left out
43 races and 21 single race mornings, with the reason
- Dublin Marathon 2026: station did not report the race window
- Austin Marathon 2022: station did not report the race window
- Los Angeles Marathon 2025: station did not report the race window
- Los Angeles Marathon 2026: station did not report the race window
- Rome Marathon 2021: station did not report the race window
- Rome Marathon 2022: station did not report the race window
- Manchester Marathon: no sourced start time
- Abingdon Marathon: no sourced held date in 2021-2026
- Athens Marathon 2025: station did not report the race window
- Berenloop Terschelling Marathon: no sourced held date in 2021-2026
- Big Sur International Marathon: no airport station within 30 km
- Bruges Marathon: no sourced held date in 2021-2026
- Carlsbad Marathon: no sourced held date in 2021-2026
- Castellón Marathon: no sourced held date in 2021-2026
- City of Oaks Marathon: no sourced held date in 2021-2026
- Cowtown Marathon: no sourced held date in 2021-2026
- Dresden Marathon: no sourced held date in 2021-2026
- Frankfurt Marathon 2026: station did not report the race window
- Geelong Running Festival Marathon: no sourced held date in 2021-2026
- Green River Marathon: no sourced held date in 2021-2026
- JTBC Seoul Marathon: no sourced held date in 2021-2026
- Kiawah Island Marathon: no sourced held date in 2021-2026
- Knoxville Marathon: no sourced held date in 2021-2026
- Kyoto Marathon: no airport station within 30 km
- Lanzarote International Marathon: no sourced held date in 2021-2026
- Lausanne Marathon: no sourced held date in 2021-2026
- Little Rock Marathon: no sourced held date in 2021-2026
- Malta Marathon: no sourced held date in 2021-2026
- Marathon des Alpes-Maritimes Nice-Cannes 2023: station did not report the race window
- Marathon Vert de Rennes 2023: station did not report the race window
- Maratón Internacional Elche-Alicante: no sourced held date in 2021-2026
- Maratona di Pisa: no sourced held date in 2021-2026
- Maratona di Ravenna Città d’Arte 2023: station did not report the race window
- Maratona di Ravenna Città d’Arte 2025: station did not report the race window
- Marine Corps Marathon 2026: station did not report the race window
- Melbourne Marathon 2022: station did not report the race window
- Melbourne Marathon 2024: station did not report the race window
- Mesa Marathon: no sourced held date in 2021-2026
- Mohawk Hudson River Marathon: no sourced held date in 2021-2026
- Nagoya Women's Marathon: nearest stations missed most race mornings
- Napa Valley Marathon: no sourced held date in 2021-2026
- Newcastle-Gateshead Marathon: no sourced held date in 2021-2026
- Niagara Falls Marathon: no sourced held date in 2021-2026
- Oslo Marathon: no airport station within 30 km
- Perth Running Festival Marathon 2023: station did not report the race window
- Rocket City Marathon: no sourced held date in 2021-2026
- Route 66 Marathon: no sourced held date in 2021-2026
- San Antonio Marathon & Half Marathon: no sourced held date in 2021-2026
- Seattle Marathon: no sourced held date in 2021-2026
- Shamrock Marathon: no sourced held date in 2021-2026
- Songkhla Marathon: no sourced held date in 2021-2026
- Split Marathon: no sourced held date in 2021-2026
- Steamtown Marathon: no sourced held date in 2021-2026
- Taipei Marathon 2025: station did not report the race window
- Tel Aviv Marathon: no sourced held date in 2021-2026
- The Woodlands Marathon: no sourced held date in 2021-2026
- Venice Marathon 2021: station did not report the race window
- Venice Marathon 2022: station did not report the race window
- Venice Marathon 2026: station did not report the race window
- Verona Marathon: no sourced held date in 2021-2026
- Wineglass Marathon: no sourced held date in 2021-2026
- Yokohama Marathon 2026: station did not report the race window
- Yorkshire Marathon: nearest stations missed most race mornings
- Zürich Marathon: no sourced held date in 2021-2026