WeatherArchive / Dew point
Dew point calculator and comfort chart
Turn temperature and relative humidity into dew point (or back again), and see how muggy that air actually feels. Dew point is the better measure of how humid it is, and this page shows why.
- Dew point
- 16.7°C
- Feels
- Sticky
- Spread (temp − dew point)
- 8.3°C
Muggy; sweat evaporates slowly.
Comfort by dew point
| Dew point | How it feels | What happens |
|---|---|---|
| below 10°C | Dry | Crisp; skin and lips can feel dry. |
| 10°C–13°C | Comfortable | Pleasant for most people. |
| 13°C–16°C | Noticeable | Starting to feel humid. |
| 16°C–18°C | Sticky | Muggy; sweat evaporates slowly. |
| 18°C–21°C | Oppressive | Uncomfortable for most people. |
| 21°C and up | Miserable | Tropical; exertion is risky in heat. |
Same air, different humidity: why relative humidity misleads
Hold the amount of water in the air fixed (a dew point of 12°C) and change only the temperature through a day. Relative humidity swings wildly; the dew point, and the mugginess you feel, does not move.
- Relative humidity
- 53%
- Dew point
- 12°C
- Comfort
- Comfortable
A cool dawn at 95% humidity can hold less water than a hot afternoon at 40%. Relative humidity is relative to what the air could hold, and warm air can hold roughly 7% more water per degree Celsius (the Clausius–Clapeyron relation).
What dew point means
The dew point is the temperature air would have to cool to, at constant pressure and moisture, for water vapour to start condensing: dew on grass, fog in a valley, sweat that won’t evaporate. Because it depends only on the amount of moisture, it tells you how humid it feels regardless of the time of day. This calculator uses the Magnus formula with the Alduchov–Eskridge coefficients, accurate to about 0.1 °C between −40 °C and 50 °C.
You can look up the historical dew point for any past day: the hourly past weather view plots it next to temperature.
Questions people ask
What is a comfortable dew point?
Most people find dew points below about 13 °C (55 °F) comfortable. Above 18 °C (65 °F) it feels sticky, and above 21 °C (70 °F) oppressive.
Is dew point or humidity better for how it feels?
Dew point. Relative humidity changes with temperature even when the air’s moisture does not, so 90% on a cool morning can feel drier than 50% on a hot afternoon.
Can the dew point be higher than the temperature?
Not in a stable state. When air cools to its dew point it is saturated (100% humidity) and extra moisture condenses out.
How do I convert dew point to relative humidity?
Choose “Humidity from temperature + dew point” above and enter both values; the page uses the inverse of the Magnus formula.