How often does weather delay flights at Lyon-Saint-Exupéry?
From January 2018 to September 2026, EUROCONTROL recorded arrival restrictions for weather (regulation reason W) at Lyon-Saint-Exupéry (LYS) on 16 of 3,190 days (0.5%). Weather caused 12% of all arrival-regulation delay minutes at this airport. Source: EUROCONTROL.
Too few weather-restriction days for monthly patterns to mean much; this page is shown for completeness.
Month by month
| Month | Days with weather restrictions | Days with ≥ 1 min per arrival | Minutes per arriving flight |
|---|---|---|---|
| January | 1% | 0% | 0.01 |
| February | 1% | 0% | 0.01 |
| March | 0% | 0% | 0.00 |
| April | 0% | 0% | 0.00 |
| May | 0% | 0% | 0.01 |
| June | 1% | 0% | 0.01 |
| July | 0% | 0% | 0.00 |
| August | 0% | 0% | 0.00 |
| September | 0% | 0% | 0.00 |
| October | 1% | 0% | 0.01 |
| November | 0% | 0% | 0.00 |
| December | 1% | 0% | 0.00 |
Share of days on which EUROCONTROL's network manager limited arrivals because of weather at or around the airport (regulation reason W), 2018–2026. Minutes per arriving flight = weather-regulation delay ÷ all arrivals that month. Worst weeks of the year: week 49 (4%), week 44 (2%), week 42 (2%).
Year by year
| Year | Days with weather restrictions | Minutes per arriving flight | Arrivals |
|---|---|---|---|
| 2018 | 6 of 365 | 0.01 | 56,686 |
| 2019 | 4 of 365 | 0.01 | 58,185 |
| 2020 | 1 of 361 | 0.01 | 22,572 |
| 2021 | 2 of 365 | 0.00 | 27,377 |
| 2022 | 3 of 365 | 0.00 | 40,282 |
| 2023 | 0 of 365 | 0.00 | 44,758 |
| 2024 | 0 of 366 | 0.00 | 45,731 |
| 2025 | 0 of 365 | 0.00 | 46,851 |
| 2026 (Jan–Sep) | 0 of 273 | 0.00 | 34,571 |
2020–2021: far fewer flights during the pandemic.
Weather among all causes
| Cause of arrival regulation | Share of delay minutes |
|---|---|
| Atc staffing | 29% |
| Atc equipment | 19% |
| Aerodrome capacity | 17% |
| Air traffic control capacity | 16% |
| Weather | 12% |
| Other | 4% |
Causes with at least 2% of all arrival-regulation delay minutes, 2018–2026.
What the weather was like on those days
| In the airport's weather reports (METAR, 05–21 UTC) | Days with weather restrictions | Other days | Ratio |
|---|---|---|---|
| Thunderstorm reported | 12% | 7.8% | 1.6× |
| Fog or visibility under 800 m | 44% | 8.5% | 5.1× |
| Cloud base at or below 200 ft | 56% | 4.8% | 11.7× |
| Gusts of 30 knots or more | 6.2% | 7.6% | 0.8× |
| Crosswind of 20 knots or more on the best runway | 0.0% | 0.4% | — |
| Snow | 6.2% | 2.0% | — |
| Freezing rain or drizzle | 0.0% | 0.2% | — |
On 12% of the restriction days none of these showed up in the airport's own reports: restrictions are also set on forecasts, for weather on the approach or elsewhere in the area, and when the wind direction forces a less efficient runway layout. The weather is what came with the delays, not proof of their cause. Based on 3,189 days with full METAR coverage.
The heaviest days
| Date and reported weather | Weather delay, minutes | Arrivals | Minutes per arrival |
|---|---|---|---|
| 20 June 2019 none of these in the airport's METAR | 280 | 198 | 1.4 |
| 21 May 2018 none of these in the airport's METAR | 219 | 143 | 1.5 |
| 1 January 2020 Fog or visibility under 800 m | 197 | 106 | 1.9 |
| 5 February 2018 Cloud base at or below 200 ft; Snow | 176 | 153 | 1.2 |
| 10 October 2018 Fog or visibility under 800 m; Cloud base at or below 200 ft | 175 | 177 | 1.0 |
What these numbers cover
- Only delays from air traffic flow management (ATFM) regulations on arrivals are counted — not all delays, not departures, and not cancellations or diversions. A day with restrictions does not mean every flight was late.
- Airport ICAO code LFLL, IATA LYS. Ranking by share of restriction days: 83 of 94 airports on this site.