The most popular and longest celebrated event in Geneva is l'Escalade (the scaling of the wall), in memory of the city's successful defense, in 1602, against the invading armies of the Duke of Savoy. When soldiers attempted to climb the city's protective wall in order to let their armies in through the city gates, Geneva's citizens managed to repel their efforts. The alarm was sounded by a woman, Mère Royaume, who was up late making soup for her family.  In order to rouse the Guard she threw her iron soup kettle (la marmite) down the ramparts.  Every year the Geneva chocolate shops make small - and some large! - chocolate copies of the "marmite", which are filled with marzipan vegetables and chocolates and sometimes little snappers.  The marmites are decorated in the Geneva colours of yellow and red and bear the city and cantonal shield with the motto "Post Tenebras Lux".

Escalade dinners are held in Geneva each year.  The traditional dish is turkey, with roast potatoes and cardons and at the end of the meal a chocolate marmite is broken (usually by the youngest person present) and this person says "Ainsi périssent les énémies de la République" !!  (Let the enemies of the Republic die).

The December 3-12 observance includes parades, exhibitions, and a torchlit procession of costumed participants at the end of the festivities. It is during this time that the names of 18 citizens, who lost their lives in the melee are called out and honored.

It's the nearest the sober Genevois get to a carnival. for more background, see the post by Hambagahle in the Tripadvisor Geneva forum:

Escalade & Marmites

The night of the Escalade is Dec 11/12; a week before that, the weekend nearest Dec 4/5, is the Course de l'Escalade, the Escalade Race, a city foot race in aid of charities for all ages graded from 6 to 60. It ends up with the Marmite parade which is in fancy dress costume. Stands offer mulled wine in return for a charity donation.

vin chaud marmite 'race'

 

The Fete de la Musique is a music festival that takes place in various locations around the city in June of every year. All types of music and dance are displayed, offering something for every taste. Americans in Geneva on Independence Day don't have to worry about missing all the fireworks and watermelon (fireworks,anyway), because Geneva shows off the largest 4th of July fireworks display outside the United States, thanks to the American International Club of Geneva. Get your seat at the Boutde-Monde Stadium as early as possible.

In late July or early August the annual "Fêtes de Genève" are held.  This gives a general carnival like atmosphere to the city, with bands playing, a procession and fireworks as well as street balls.

The months of November through January are a festive time in Geneva as the Christmas Festival takes place. Activities and events take place throughout the city: The International Christmas Market at Fusterie Square, skating at Place du Rhone, and the annual Christmas "Polar Bear Race" or swimming  race in the icy waters of the river Rhône are just part of the fun.

Geneva Tourism - Events Calendar - What's On Info