'Forces of Nature' will feature five maps, including two remakes from previous games, and all have a shared theme of strong weather activity.
'Aftermath' is set in a government park that was struck by a tsunami, and features a ship washed up on top of buildings and high amounts of standing water.
'Artillery' is a former COG missile silo where players fight on the edge of a persistent storm.
The final new map is 'Cove', a stranded seaside port that is regularly blanketed by fog.
Of the remakes, 'Raven Down' from the first Gears of War is an infamous close-quarters map that is now covered in snow.
Finally, Gears of War 2's 'Jacinto' now features high levels of dangerous emulsion and Lambent stalks.
> Read our Gears of War 3 'Forces of Nature' interview with Epic's Rod Fergusson
Elsewhere, 'Forces of Nature' will feature four new characters, three of which - Commando Dom, Mechanic Baird and Savage Grenadier Elite - are based on pre-order bonuses but with unique colours, and are branded as Limited Edition.
The new character, Savage Hunter, is a based on a breed of sand people out in the deadlands.
Seven new weapon skins will also be available, two of which are tied to an Achievement Easter Egg, and one coloured blue and red for Major League Gaming.
Finally, Gears of War 2 mode Guardian, which was the basis for the Capture the Leader mode, will make a comeback.
'Forces of Nature' will be the fourth and final release in Gears of War 3's Season Pass, and comes with an additional 10 Achievements worth 250 Gamerscore.
It will be available from March 27 for 800 Microsoft Points (£6.80 / $10).
The last title update for the game fixed a variety of bugs and glitches.
Previous DLC pack 'Fenix Rising' added five new multiplayer maps.
> Read our review of Gears of War 3