It feels like Sydney is getting muggier for longer.
Some of us feel like we walk around wrapped in sweaty, suffocating cling wrap for months on end.
Others may love the heavy air.
If you think Sydney is getting more humid, more often, you're not wrong.
Why does it feel more humid in Sydney?
The increasing humidity in Sydney is primarily driven by higher ocean temperatures, which lead to increased evaporation and more moisture in the atmosphere.
The Tasman and Coral Seas are now 1–3°C above 'normal', causing higher evaporation rates.
Winds blowing from the north or northeast bring this moisture from the warm ocean onto the coast, resulting in high dew points.
When will the humidity ease? Looking at the Bureau of Meteorology's historical data from recent years, it's likely to be May before the humid weather takes a reliable break.
We spoke to Professor of Heat and Health at the University of Sydney, Ollie Jay, to find out how humidity affects us.
Humidity quick facts
- The hotter the air temperature, the more water it can hold.
- A day with a temperature of 25 degrees at 70% humidity will feel similar as a 40 degree day with 30% humidity.
- Humidity prevents sweat evaporating, which is how our body cools itself down.
- It’s one of 4 factors that determine overall temperature. The other 3 are air temperature, radiant heat from the sun and conductive heat from surfaces like the ground.
- Air temperatures on weather reports are often measured in the shade. You're not imagining it if you feel hotter.
- The times of peak risk to our health don’t necessarily coincide with peak temperature when there’s high relative humidity and little wind. Use Heatwatch to know your risky times.
- Domestic violence and suicide attempts increase in warm and humid weather. And the affects of depression are more severe. The causal links are not yet known. Studies are currently looking at this.
- Humidity affects everyone differently. It may be a risk for others even if you don’t feel it.
Tips to cool down
- If you don't have air-conditioning, fans are your best friend. You need air movement to help move the sticky sweat from your skin. Wetting your skin with water and being in areas with fans can be effective.
- Plunge your feet in an ice bath.
Know your risk - a useful tool
- Certain people are more at risk in warm and humid conditions. The University of Sydney developed HeatWatch to help you understand your own risk profile. You can also create profiles for older people in your life. The app will help you understand which times of day are the safest to take part in physical activity.
Watch Professor Ollie Jay talk about how humidity affects us, why people should care about it, and the difficulty of weather reports.
