How often does weather delay flights at Grenoble-Isère?
From January 2018 to September 2026, EUROCONTROL recorded arrival restrictions for weather (regulation reason W) at Grenoble-Isère (GNB) on 17 of 3,115 days (0.5%). Weather caused 32% 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 | 3% | 1% | 0.90 |
| February | 0% | 0% | 0.19 |
| March | 1% | 1% | 0.24 |
| April | 1% | 0% | 0.28 |
| May | 0% | 0% | 0.00 |
| June | 0% | 0% | 0.00 |
| July | 0% | 0% | 0.00 |
| August | 0% | 0% | 0.00 |
| September | 0% | 0% | 0.00 |
| October | 0% | 0% | 0.00 |
| November | 0% | 0% | 0.03 |
| December | 1% | 1% | 0.11 |
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 3 (5%), week 13 (3%), week 4 (3%).
Year by year
| Year | Days with weather restrictions | Minutes per arriving flight | Arrivals |
|---|---|---|---|
| 2018 | 3 of 354 | 0.03 | 3,716 |
| 2019 | 3 of 354 | 1.03 | 3,610 |
| 2020 | 0 of 340 | 0.00 | 2,698 |
| 2021 | 1 of 357 | 0.02 | 2,563 |
| 2022 | 2 of 352 | 0.40 | 3,494 |
| 2023 | 0 of 360 | 0.00 | 3,283 |
| 2024 | 2 of 363 | 0.04 | 3,873 |
| 2025 | 4 of 362 | 0.30 | 4,148 |
| 2026 (Jan–Sep) | 2 of 273 | 0.01 | 3,339 |
2020–2021: far fewer flights during the pandemic.
Weather among all causes
| Cause of arrival regulation | Share of delay minutes |
|---|---|
| Weather | 32% |
| Aerodrome capacity | 29% |
| Air traffic control capacity | 23% |
| Equipment (non-atc) | 13% |
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% | 1.5× |
| Fog or visibility under 800 m | 59% | 3.8% | 15.3× |
| Cloud base at or below 200 ft | 18% | 0.5% | — |
| Gusts of 30 knots or more | 5.9% | 3.6% | 1.7× |
| Crosswind of 20 knots or more on the best runway | 0.0% | 1.8% | — |
| Snow | 18% | 3.8% | 4.6× |
| Freezing rain or drizzle | 0.0% | 0.4% | — |
On 24% 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 3,109 days with full METAR coverage.
The heaviest days
| Date and reported weather | Weather delay, minutes | Arrivals | Minutes per arrival |
|---|---|---|---|
| 19 January 2019 Fog or visibility under 800 m | 2,694 | 44 | 61.2 |
| 23 February 2019 Fog or visibility under 800 m | 962 | 83 | 11.6 |
| 15 March 2025 Fog or visibility under 800 m; Cloud base at or below 200 ft; Snow | 901 | 42 | 21.5 |
| 2 January 2022 Fog or visibility under 800 m; Cloud base at or below 200 ft | 728 | 32 | 22.8 |
| 2 April 2022 Fog or visibility under 800 m; Snow | 673 | 28 | 24.0 |
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 LFLS, IATA GNB. Ranking by share of restriction days: 79 of 94 airports on this site.