Virtual Weather is an umbrella term for meteorological phenomena on Lyoko, Replikas, other virtual worlds like the Cortex and the Volcano Replika, and in the Digital Sea. This article lists the various observed kinds.
X.A.N.A. showed the ability to create sandstorms in "Log Book", in the form of a large tornado. This decreased visibility significantly and made moving around the plateau much harder. X.A.N.A. used it to hide a Megatank and later to ambush Yumi and Aelita by destroying the plateau and trapping them on a small platofm. This has only been observed in the Desert Sector.
Mountain Fog is exactly what it sounds like. It is fog in the Mountain Sector. This is always present in the Mountain Sector to some degree covering some mountains and the whole Digital Sea. However, sometimes it can get a lot thicker. This thickening was first observed in "Tip-Top Shape" and later in "Revelation". In "Tip-Top Shape", X.A.N.A. fogged over the entire sector to make it harder to navigate and for Aelita and Yumi to find and deactivate the tower. In "Revelation", it was used to hide the approach of 3 Tarantulas to the tower which was used to decode Franz Hopper's diary.
Digital Sea Flooding
In "Tidal Wave", the Digital Sea overflowed, and flooded the plateaus and platforms of the surface sectors with the sea. This was also caused by X.A.N.A., and had to be repaired in Sector Five. This did not affect the towers or the sectors, but was lethal to monsters and avatars.
In most appearances of the Cortex, a lot of clouds are visible beyond the land of the sector. The clouds surround the area, but don't touch it directly. Instead, there appears to be a buffer zone of neither land nor clouds, which is about half as wide as the land covered part of the Cortex itself. This also appears in the concept art.
In Evolution, the Desert Sector seems to have the clouds very similar to those seen in the Cortex.
Glacial Expansion and Contraction
Rather than being a natural phenomenon, the growth and shrinking of ice in the Ice Sector appears to be entirely artificial. In "Down to Earth", Jeremie's Multi Agent System was used to radically expand the ice in the Ice Replika, to constrain the Kolossus. In several episodes, such as "Saint Valentine's Day" and "Vertigo", Aelita used her Creativity to expand the ice to constrain or block enemies.
Glacial Breakup and Drift
Like Glacial Expansion and Contraction, Glacial Breakup and Drifting is mostly artificial. In "Temptation", Ulirch and Odd both damaged the ground with their weapons, causing it to fracture and break up. Rather than being a discrete landmass, the area became a bunch of small glaciers. Due to everyone moving on them, as well as the normal water physics in the Ice Sector, the glaciers shifted around a lot.
Digital Sea Waves
Despite looking peaceful at a distance, the surface of the Digital Sea is actually very turbulent. The waves are obvious in any shot close to the surface. In "Code Lyoko Evolution", this effect was toned down a little.
Like the Digital Sea, the lava in the Volcano Replika has a turbulent surface layer, when observed closely. This is actually rendered using the same effects and animation object recolored. This phenomenon was only observed in "Code Lyoko: Fall of X.A.N.A." and "Code Lyoko: Quest for Infinity".
Virtual Water is the presence of ponds on Lyoko. Unlike the Digital Sea, it is completely harmless and mostly decorative. It can be seen in the Ice and Forest Sectors. In the Forest, it was seen in "Holiday in the Fog", "Uncharted Territory" (for a very brief moment), "Temptation", "Opening Act", "Fight to the Finish" and "Quest for Infinity". In the Ice Sector, it is extremely common. In "Vertigo", Odd swam in it so he could sneak past a couple of Hornets in order to save Aelita from the Scyphozoa. The virtual water is also present inside many caves which entrances are next to waterfalls. The monsters cannot swim in the water so whenever they fall into the water they immediately drown - such as Tarantulas in "Temptation" or Bloks and Kankrelats in "X.A.N.A. Awakens, Part 2".
Earthquakes are one of the more common phenomenon in both the virtual and real world. In "Just in Time", X.A.N.A. caused a chain of earthquakes in Boulogne-Billancourt. X.A.N.A. also caused several earthquakes mentioned but not shown in the video games "Quest for Infinity" and "Fall of X.A.N.A.." The most common example of earthquakes is in the Cortex. There, earthquakes typically precede the Cortex Shifts.
Cortex and Sector Five Shifts
Cortex and Sector Five Shifts are two closely related phenomenon. In Sector Five, the Sector Five Replika, and the Cortex; the massive blocks that the sector is made out of can shift around. In the case of the Cortex, this is a security feature/ byproduct of incomplete code. In the Sector Five Replika, this was a security feature left in place by X.A.N.A., after he copied the code for the original Sector Five.
In Sector Five's case, this phenomenon is highly diverse. It occurs in the key chamber whenever one hits a Key Mechanism, allowing them to climb. It also occurs whenever the Sector Five Security Countdown hits zero, potentially trapping or devirtualizing the victim. Other instances include whenever the Transport Orb arrives in the Core Zone, as the sector rearranges. Some block shifting is also present in the form of a trap. Variations of this include collapsing floors, shifting floors, people being crushed, etc. In the video games, Sector Five shifting is a major obstacle. Finally, whenever somebody hits the key mechanism before the countdown hits zero, some blocks shift to reveal the elevator.
This phenomenon is extremely dangerous. In "Exploration" and "Cortex", several people were devirtualized by being crushed, and weren't easily re-materializeable. This was rectified by configuring the sectors to work with the materialization program. People also can get trapped, which happened to Aelita.
A point of confusion is the incident in "Plagued", when a massive platform in the Desert Sector rotated to a 90 degree angle. This wasn't a natural phenomenon. This was X.A.N.A. using the Sector Alteration Program.
Sector Collapse and Deletion
Sector Collapse and Deletion is a rare phenomenon that occurs to sectors or Replikas when the hardware that supports them is damaged, or the software supporting them is halted or fails. In non-Cortex areas, the phenomenon, as observed in the sector, consists of the colored panels of the sector dissolving away in patches, with the vector lines receding afterwards, in patches. This includes the dissolution of Lyoko Wires and towers. In the Cortex, this consists of the various modules of the Cortex falling into the Digital Sea in pieces, in a pattern emanating outward from the center. In worlds where the sector in question is the only sector, such as Replikas, the Virtual World Shell usually explodes afterwards.
- "Common Interest": This was a partial example. It occurred in the Ice Sector, and caused by a dying battery in the Supercomputer.
- "Lyoko Minus One": This was the first complete example. It occurred in the Forest Sector. The cause was the use of Code: XA.N.A. in a way tower.
- "The Pretender": It occurred in the Desert Sector. The cause was the use of Code: X.A.N.A..
- "Sabotage": It occurred in the Ice Sector. The cause was the use of Code: X.A.N.A..
- "Double Trouble": It occurred in the Mountain Sector. The cause was the use of Code: X.A.N.A..
- "Bragging Rights": Forest Replika, Supercomputer Sabotage.
- "Hard Luck": Desert Replika, Supercomputer Sabotage.
- "A Space Oddity": Sector Five Replika, Supercomputer Sabotage.
- "Fight to the Finish": Ice Replika, plus a bunch of others, Jeremie's Multi Agent Program.
- "Ultimate Mission": The Cortex, a virus.
- "Code Lyoko: Quest for Infinity": Desert Replika, Forest Replika, Ice Replika, Mountain Replika, and the Volcano Replika, multiple causes, including supercomputer sabotage and Code: Chimera.
- "Code Lyoko: Fall of X.A.N.A.": Desert Replika, Forest Replika, Ice Replika, and Mountain Replika; supercomputer sabotage.
Volcanic Plumes and Lava MovementWithin the Volcano Replika in Quest for Infinity and Fall of X.A.N.A.; the lava isn't static. The Volcano Replika has a massive sea of lava at its bottom instead of a normal Digital Sea. This lava is prone to turbulence. This is Lava Movement. The lava can sometimes plume out of volcanoes. This is a terrain hazard in Quest for Infinity and is merely a background element of Fall of X.A.N.A..
In the digital sea, the normal lighting is blue. This can be either dark or bright depending on proximity to light emitting things such as signs virtual world's, explosions, and the creation or restarting of virtual worlds.
The Cortex has ambient light from outer areas. However, areas where the light doesn't reflect, such as sealed areas and shadowed areas are darker. The core also has another light source in the form of a console.
Sector Five has more ambient lighting within the dome. Despite most stuff being blue, entities such as monsters maintain their normal colors. This light is not uniform. Certain areas, such as the area surrounding the Skidbladnir Hangar, are slightly darker. The area surrounding the dome is darker as well.
Certain incidents, such as Aelita Schaeffer dying, can make all of Lyoko darker, including completely darkening the core between the surface sectors. Certain problems, such as the Supercomputer's battery failing, can cause entities to render without color. Guardians and Simulation Bubbles can emit light.
All of the surface sectors experience both ambient light, plus light from Sector Five if not within a Replika. The ambient light is darker in the Ice Sector and Ice Replika, with the light from Sector 5 darkening after Season 1. The other surface sectors became brighter after season 1.
Virtual Atmospheric Turbulence
"Seeing Is Believing" is the only episode to feature an Oasis so far. It is located in the Desert Sector, surrounded by a wall of a few large rocks and several smaller ones and a few shrubs. In the middle, there is a pool of Virtual Water. However, this is only an illusion; this is actually a surface layer which conceals a passage to the lower platform of the sector where the activated tower was located.