* UFO sightings gradually built up in the area or there is a sudden influx of sightings in an otherwise quiet region.
* UFO sightings were bunched up or concentrated in a fixed geographical area or region.
* Duration of a UFO wave is about 2 weeks to 3 months or slightly longer.
* Long duration waves usually have two peaks with a lull period in between. Usually 4 weeks of sightings, then a drop in sighting reports for 4 weeks and finally another burst of UFO activities for another 4 weeks.
* There is a progression of wave area in time and space, for example, if it started in the south but later will moved northwards etc.
* Most of the sighting locations are arranged or orientated along straight lines (see works by Aime Michel of France).
* Most landings and humanoid encounters usually occurs during a UFO wave.
* Several types of UFO entities were reportedly seen in the same wave area (see 1973 SE USA wave). However, usually one type predominates in the wave area (see 1954 French wave).
* UFO wave follow a 10-year cycle (plus or minus 1 year) around the Earth.
* A major UFO wave sometimes create a second front in another continent. If the main wave area shifted its geographical area, its second front will also changed accordingly like a see-saw effect (see works by Ahmad Jamaludin).
* Some wave area reported the occurence of sonic booms, upper air concussions or thunder-like sounds. This phenomenon however does not occur regularly.