The shortest accurate answer
Fireflies are observed throughout the year at one monitored local site.
Abundance varies. Sightings cannot be guaranteed, and that local pattern cannot automatically be generalized across Ben Tre.
What the local baseline reports
Warmth
Warmer periods appear stronger in local experience.
Retrospective local knowledgeRain
Light rain does not necessarily stop visible activity. Some evenings after light afternoon rain appeared stronger.
First-hand / retrospective observationMoonlight
No obvious short-term effect has been noticed by the observer.
Local observation—not proof of no effectTide
No obvious short-term effect has been noticed by the observer.
Local observation—not proof of no effectWhat those observations cannot show
Can a sighting be guaranteed?
No. Fireflies are wildlife. The project records observations, not promises. Safety, visibility, river access and disturbance also affect whether an evening observation is practical.
See how future observations will be recorded →