How dew point calculator Works
What dew point actually is
The temperature at which air becomes saturated — cool it to the dew point and water condenses. It measures actual moisture content, unlike relative humidity (which changes with temperature even when moisture does not). The Magnus formula computes it from temperature and RH to within ~1°F across normal ranges.
The comfort scale
- Below 50°F: dry — desert-crisp, static-electric air.
- 50–60°F: comfortable — most of the temperate world's pleasant days.
- 60–65°F: noticeably humid — the first "sticky" note.
- 65–70°F: uncomfortable — the Gulf Coast's summer baseline.
- 70°F+: oppressive — tropical; everything feels damp, including your thoughts.
The practical payoffs
- Comparing cities fairly: Phoenix at 30% RH and 100°F holds less moisture than New Orleans at 50% RH and 85°F — dew point shows it; RH hides it.
- Condensation planning: surfaces below dew point collect water — cold drinks sweat, windows fog, AC ducts drip.
- Running comfort: dew point below 55°F is perfect racing weather; above 65°F, pace expectations drop 1–2% per dew point degree.