Here are some popular events that take place in Bregenz, Vorarlberg, Austria by month:

January:

- Vorarlberg Winter Festival: An annual festival celebrating winter sports, music, and culture.

February:

- Fasching (Carnival): Celebrated with parades, costume parties, and traditional events.

March:

- Bregenz Spring Fair: A traditional fair featuring local goods, food, and entertainment.

April:

- Bregenz Easter Market: A market selling Easter-themed goods and treats.

May:

- Bregenz Harbor Festival: A lively event celebrating the opening of the harbor season with music, food, and activities.

June:

- Bregenz Festival: One of the most famous events in Bregenz, showcasing opera performances on a floating stage on Lake Constance.

July:

- Bregenz Lake Festival: A summer festival with music, dance, and entertainment along the lakeshore.

August:

- Bregenz Seefest: A lakeside festival with fireworks, live music, and a variety of activities.

September:

- Bregenz Street Food Market: A market featuring a variety of international food stalls and vendors.

October:

- Bregenz Wine Festival: A celebration of local wines with tastings, food pairings, and music.

November:

- Bregenz Christmas Market: A festive market selling handmade gifts, decorations, and traditional Austrian treats.

December:

- Bregenz New Year's Eve Celebration: A lively event with fireworks, music, and festivities to ring in the new year.

Please note that event dates and details may vary each year, so it's always a good idea to check for the most up-to-date information closer to the time of your visit.