Temperature & Airsoft FPS: Gas Guns in Cold

Question:

How does temperature affect FPS output in a gas airsoft gun?

Answer:

Temperature plays a significant role in how a gas-powered airsoft gun performs on the field. Gas propellants like Green Gas and CO2 are pressure-dependent, meaning their output fluctuates directly with ambient temperature.

In warmer conditions, gas molecules move faster, increasing internal pressure and pushing BBs at higher FPS. On a hot summer day, a gun that chronographs at 350 FPS indoors could spike noticeably higher outside. This is why many players use lower-power gases like Red Gas or adjust their loadout during summer events.

In colder temperatures, the opposite occurs. Pressure drops, and your gun may cycle inconsistently or produce significantly lower FPS — sometimes dropping 50–100 FPS in near-freezing conditions. CO2 generally handles cold weather better than Green Gas due to its higher stored pressure, making it a popular choice for winter players.

HPA (High-Pressure Air) systems are the most effective solution to temperature inconsistency. Since HPA uses regulated, compressed air, your FPS output remains consistent regardless of weather conditions.

Keep in mind that field limits around 350–400 FPS for rifles are common in North America, so always chronograph before play — especially when temperatures shift between seasons.

Running an HPA or mag-fed setup?

Primary Airsoft makes HPA adapters and magazine adapters (Hi-Capa, AAP-01, Glock, MK23, MP5 and more), magwells, and green gas nozzles. Shop them at primaryairsoft.us.