Does Humidity Affect Fluorescent Lights?

A fluorescent light is a type of gas-discharge bulb that uses electricity and mercury vapor to produce a visible light.

Hermetic Seal

Fluorescent bulbs use lower amounts of energy than incandescent light bulbs.Fluorescent bulbs use lower amounts of energy than incandescent light bulbs.
According to J. R. Coaton and A. M. Marsden, authors of "Lamps and Lighting," the process within a fluorescent light is complex and easily disrupted by external factors such as high humidity.

According to Junior Energy, fluorescent bulbs use a hermetic seal, which means no humidity will penetrate the bulb itself. This seal is necessary to keep the toxic mercury vapor from leaking out into the environment.

Corrosion

Humidity can cause corrosion of the metal fixtures on the ends of a fluorescent bulb, impeding its ability to transmit electricity. The corrosion is easily avoidable by purchasing a weatherproof fluorescent bulb, as they are resistant to corrosion.

Condensation

Excess buildup of condensation on the outside of the bulb can cause it to take longer to turn on, write Coaton and Marsden. The temperature difference on the glass negatively affects the delicate process within. Wiping the condensation off the bulb and waiting for five minutes will remedy the problem in most situations. Additionally, purchasing a weatherproof fluorescent bulb will avoid the problem altogether.