Turn off raids in the game settings
Open the game settings, look for the storm raid toggle, and turn it off. Roboto Games added a dedicated switch in the October 20 demo update, so you can change the raid setting directly. The developer’s demo patch notes list the toggle without specifying an exact submenu.
Check your build if the setting is missing
The update that added the switch was v0.1.036.28374. Check the version shown on the main menu. If you are still on an older demo, save and exit so Steam can apply the update, then check the settings again.
Keep shelter ready for storm warnings
Use the toggle for the raid portion of the event. The patch notes do not say that switching it off also removes roaming chaos storms. Keep your pillar shelter ready, and read any other world settings separately if you want to change storm danger more broadly.
FAQ
Is the raid switch the same as changing overall difficulty?
The demo notes list a dedicated raid toggle. Start with that option if your goal is to stop raids.
Can I turn off raids on an older demo?
The switch was introduced in v0.1.036.28374. If your demo predates that update, install a newer build and check again.
Does disabling raids remove the storm itself?
The documented switch is for raids. Plan for storm warnings and keep a place to shelter.