Jersey Airport (JER), Guernsey Airport (GCI) and Alderney Airport (ACI), located in the Channel Islands, frequently experience significant fog during the winter months, which often disrupts commercial flight operations. This phenomenon is primarily due to the region’s unique maritime climate and geographical position.
In the winter of 2023 (between September 01 and March 01) we tracked 178 diverting aircraft at these two airports. Whilst we can’t be sure that all of these were due to weather, a significant portion of them likely were. What is it that makes the channel islands so susceptible to fog?
The most prolific passenger airlines operating to the Channel Islands’ airports are Blue Islands (GR/AUR), Aurigny (SI/BCI), British Airways (BA/BAW) and easyJet (U2/EZY).
Why are the Channel islands always foggy in the winter?
- Maritime Climate: The Channel Islands are surrounded by the relatively warm waters of the English Channel. During winter, when colder air masses move over the warmer sea surface, the temperature difference can lead to condensation and the formation of sea fog. This type of fog can drift inland, blanketing the airports.
- Topographical Influence: The low-lying nature of Jersey and Guernsey airports amplifies fog accumulation. With no significant elevation to disperse the fog, it tends to linger longer, particularly during periods of low wind.
- Radiation Fog: On clear nights with minimal wind, the ground loses heat rapidly, cooling the air close to the surface. When the air temperature drops to its dew point, radiation fog forms. This is a common occurrence during the longer winter nights in the islands.
Fog significantly reduces visibility, which is a critical safety factor in aircraft operations. Modern commercial aircraft are capable of performing instrument approaches, enabling them to land in incredibly limited visibility.
However, some smaller regional aircraft (which frequently service Jersey and Guernsey) may have tighter limitations in handling such conditions. Additionally, operational minima for takeoff and landing at these airports can result in delays or diversions during dense fog episodes.
Airports in the Channel Islands invest in high-intensity runway lighting systems and ground-based navigational aids to enhance visibility for pilots. Airlines also work closely with meteorological services to plan schedules and adjust operations proactively during expected foggy conditions.
Despite these measures, passengers traveling to or from Jersey and Guernsey during the winter should anticipate potential disruptions and maintain flexibility in their travel plans. Understanding the local climate dynamics is key to managing expectations and ensuring travel safety.
Have you experienced fog in the Channel Islands? Let us know in the comments.
Cover photo: Thomas Masterman, JetPhotos
