Snowmaking Temperature Calculator

Snow guns work by atomizing water into fine droplets, and as those droplets fall through the air, evaporation cools them below the surrounding air temperature — that extra cooling is what actually freezes the water into snow crystals. Wet bulb temperature accounts for both dry air temperature and humidity together, so it reflects the true freezing potential of the air, while dry bulb temperature alone can make marginal conditions look better than they really are.

Lower relative humidity means the air can absorb more moisture before saturating, which drives more evaporative cooling as water droplets are sprayed into it. In the Stull formula this shows up as a lower computed wet bulb temperature at the same dry bulb reading, so a dry 25°F day can actually support better snowmaking than a humid 25°F day.

The calculator applies roughly 0.5°F of wet bulb adjustment per inch of mercury the barometric pressure deviates from the sea-level standard of 29.92 inHg. Mountain resorts commonly sit at 24–28 inHg, which works out to a wet bulb shift of about 1-3°F relative to sea level — meaningful near the 27°F threshold, but small compared to the effect of getting the humidity reading right.

Can Make Snow is a strict yes/no cutoff at 27°F wet bulb — at or below that, snowmaking is technically feasible. Snow Quality is a finer 1-5 scale layered on top of that same wet bulb number: readings right at the 27°F edge still register as feasible but only rate a 2 (marginal, wet/heavy snow), while readings well below 10°F rate a 5 (excellent, dry, fluffy snow). A 'yes' on feasibility doesn't mean the snow produced will be good snow.

The calculator uses a stepped lookup tied to the same wet bulb bands as the quality rating, rather than a continuous formula — 80,000 gallons at the coldest, most efficient conditions up through 250,000+ gallons near the marginal cutoff. This reflects the real-world pattern that colder air converts a much higher fraction of sprayed water into snow rather than losing it to runoff or incomplete freezing, so efficiency degrades sharply, not gradually, as wet bulb temperature climbs toward the threshold.