how many sharknado movies are there

There are six main Sharknado movies in the official series. These are:

1. Sharknado (2013)
2. Sharknado 2: The Second One (2014)
3. Sharknado 3: Oh Hell No! (2015)
4. Sharknado: The 4th Awakens (2016)
5. Sharknado 5: Global Swarming (2017)
6. The Last Sharknado: It's About Time (2018)

In addition to these six, there are also three spin-off movies related to the Sharknado franchise, but the main series consists of six movies.