Weather

Weather is a Gameplay Mechanic in Fortnite: Battle Royale. It was introduced in Season 6, but was introduced outside of events in Chapter 2: Season 8.

Description
Weather is a dynamically shifting gameplay mechanic within each match of Battle Royale. Weather is split two types:

Weather Events
Weather Events are localised and randomised events which can happen multiple times a match, but only in one location at a time. Currently there are only two weather events, these being Tornados and Lightning Storms.

Visual Weather
Visual Weather is a type of weather in which the only change is the aesthetic of the map, with restrictions to visibility. These will occur across the entire map at once, and will either appear during specific in game events, or periodically in normal matches.

Tornado
Tornados take twenty-five seconds to form and will last roughly eight minutes. Tornados will suck up and throw props around the environment, similar to how they can be moved with a Grab-itron or Saucer, and will pull nearby players into it and upwards, allowing for Glider Redeploy. Tornados are localized and will slowly move across the map.

Lightning Storm
Lightning Storms take eight seconds to form and will last roughly three minutes. Webs of lightnings will occasionally appear on the ground shortly before a lightning strikes from the stormy clouds. Players will take 10 damage if they are struck by a lightning, but gain a movement speed boost when hit. It can strike 2-3 players at once. Players are more likely to get struck by a lighting when on a high area or when swimming. Lightning Storms will also create fire.

Fog
Fog was first seen in Chapter 2: Season 8, as a periodic weather change which affected the whole island at once. Fog makes visibility difficult, but does not change any gameplay mechanics. It will dissipate after a short time.

Blizzard
Blizzards have only appeared during the 2019 iteration of Winterfest. They functioned very similar to fog, appearing across the entire island at once and dissipating after a short time.

Permanent Fog
Permanent Fogs have appeared several times in different Fortnite events. Fortnitemares 2020, for example, had a thick purple Fog across the entire island for the entirety of the event, but only during night time.

Earthquakes
Earthquakes were introduced during Chapter 3: Season 1. They randomly appear around drilling areas of Imagined Order. During an earthquake, the ground and the camera starts trembling and all props and builds in the area receive damage in large increments.

Season 6

 * Update v6.00: The entire Island is covered in a mist during Season 6 and made it slightly more difficult to see.
 * Update v6.20: The mist got thicker and turned into a fog for the start of Fortnitemares, making it significantly harder to see.
 * Post-Butterfly Event: Fog has dissipated.

Season 7

 * Ice Storm: Fog returns for the period of the event.

Chapter 2: Season 1

 * Update v11.30 (Winterfest): Introduced Blizzards. They will appear at random and get more intense as the days pass, they'll apply to the entire island at once. They will also dissipate at random.
 * End of Winterfest: Removed Blizzards.

Chapter 2: Season 4

 * Fortnitemares 2020: Midas' Revenge: Fog returns with a dark purple color. It only appears at night.

Chapter 2: Season 8

 * Update v18.00: Fog returns, with it being dynamic and randomly appearing and dissipating throughout the match.

Chapter 3: Season 1

 * Update v19.00: Fog slightly altered, changing its color from white to more blue.
 * Content Update v19.01 #2: Tornados and Lightning Storms are introduced, after being teased in the season trailer.
 * 13th January 2022: Changes to weather:
 * The maximum amount of vehicles that can be present in a tornado has been increased from 1 to 2.
 * The maximum amount of physics objects in a tornado have been increased from 50 to 75.
 * 14th January 2022: Changes to weather:
 * Tornado chance increased from 80% to 100%, meaning each game will have at least one tornado.
 * Tornado can now spawn in first 6 storms circles, previously 5.
 * Delays between a new Tornado reduced from 3 minutes to 2 minutes.
 * Delays between a new Lightning storm reduced from 3 minutes to 2 minutes.
 * 17th January 2022: Tornados spawn less frequently.

Trivia

 * Some locations such as Misty Meadows had visible mist in the area. This was not as thick as a fog, but noticeable as the mist was localised to that area only.