How cold is the water right now?
Coldest measured this morning: Outlet of Lac la Martre in Canada, 0.1 °C. Warmest: Port O'Connor, 32.2 °C. Every number on this page comes from a real station with its measurement time. Guesses do not get in.
Where the world's water sits today
All measured stations sorted into the bands the app uses, from ice bath to bathtub. The bar is the share of stations in each band right now.
Glacier water, with a name
The first minute decides
Below 15 °C the body answers with the gasp reflex: an involuntary breath in, sixty to ninety seconds of racing pulse. Enter slowly, keep your face out until breathing settles, stay close to the exit, never swim alone. Below 10 °C, minutes count, not laps. The app shows a per-sport verdict for every measured spot and warns when your favourite drops below your own threshold.
A station measures where it stands, usually at a gauge or a buoy. The pool below the waterfall you are eyeing may be colder still. Read the value, read its time, then look at the water.
Why is the water so much colder than the air?
Water stores roughly four times more heat per degree than air, so it warms and cools far slower. A 28°C summer day can sit over a 16°C lake — which is exactly why measured values beat guesses.
What water temperature is comfortable for swimming?
Most people find 22–26°C comfortable. 18–22°C is fresh, below 15°C is cold-water territory where exposure time matters, and below 10°C is for experienced cold-water swimmers with proper precautions.
Where do these values come from?
From official measuring stations: NOAA and national buoys, USGS river gauges, agency monitoring networks. Every value on this page carries its own measurement time — no estimates.
Know before you go.
Every measured station worldwide with history, BrrScore and cold-water alerts, free in the app.
Download on the App Store