Fireworks are pyrotechnic devices that produce light, sound, and smoke through chemical reactions. These devices rely on precise chemical compositions to ignite and create their intended effects. Rain can significantly interfere with their performance, as water affects the delicate balance required for a successful display.
How Rain Affects Fireworks Performance
Rain profoundly impacts fireworks because their chemical components are highly sensitive to moisture. A primary ingredient, black powder, consists of potassium nitrate, charcoal, and sulfur. Potassium nitrate is water-soluble; if black powder becomes wet, it can leach out, ruining the mixture and preventing proper ignition or causing it to burn very slowly.
Moisture directly interferes with the ignition system, which includes fuses and, for professional displays, electrical components. Water can dampen or extinguish fuses, leading to misfires or complete failure to launch. Even if ignition occurs, water can dilute or deactivate the chemical compounds responsible for color, vibrancy, and specific effects. High humidity in the air, even without direct rain, can also affect the chemical composition of fireworks, making fuses harder to light and potentially causing less vivid colors.
Safety Concerns in Wet Weather
Operating fireworks in wet conditions introduces several safety hazards. Rain can cause fuses to become unreliable, leading to misfires or “duds” where the firework fails to ignite or launch as intended. A firework that has absorbed moisture might not launch properly but could still explode on the ground, posing a danger. For professional displays utilizing electrical firing systems, rain and wet ground present electrical shock risks to operators.
Wet surfaces also create slippery conditions for both individuals setting up fireworks and spectators, increasing the risk of falls. The stability of launching equipment can be compromised on wet ground, leading to improper aiming or tipping of devices. These combined factors often lead organizers to postpone or cancel displays during heavy rain or thunderstorms.
Managing Fireworks in Rainy Conditions
Professional firework displays are generally more resilient to rain than consumer fireworks. Pyrotechnicians often use electrically fired systems, eliminating the need to manually light fuses. They also weather-proof their setups by covering firework tubes and shells with thin plastic sheeting or cling film. This protective covering keeps the fireworks dry but is thin enough to be fired through without affecting the display. While light rain typically does not stop professional shows, heavy downpours may lead to delays or cancellations.
For consumer fireworks, using them in the rain is generally not recommended due to safety and performance issues. If fireworks get wet, they should not be allowed to dry out and be reused.
Instead, damaged, unused, or unexploded fireworks, including those that have become wet, should be carefully submerged in a bucket of water until completely saturated. After soaking, they should be double-bagged in plastic to keep them wet and then disposed of in regular household trash, never in recycling.