One check before you drive to the water.
Port O'Connor measures 90 °F, Tutak C in Alaska 32. NOAA buoys, USGS river gauges, tide stations, estuary reserves and EPA beach ratings, every value with its measurement time. No models on this page.
6 regions, one honest number each
Warmest measured spot per state
Warm water, rated water
Key West / Smathers BeachEPA: fair87 °FKey West, FLEPA: good87 °FKey WestEPA: good87 °FMarathon / Sombrero BeachEPA: good86 °FArecibo, Puerto Rico (249)EPA: closed risk86 °FPlaya Caza y PescaEPA: closed risk86 °FPlaya El MuelleEPA: closed risk86 °FSan Juan, PREPA: good86 °FEPA BEACON ratings for 358 beaches sit next to the measured temperature. A warm beach with a poor rating is still a poor beach.
Measured, never modeled
NOAA's National Data Buoy Center runs the offshore buoys, NOAA CO-OPS the tide stations, the USGS thousands of river gauges, the NERRS estuary reserves their sondes, and the EPA rates the beaches. BrrChecker reads them every three hours and shows the time of every measurement. The few Open-Meteo model points we carry for the US are not on this page.
A buoy measures where it floats: a mile offshore the water can be five degrees cooler than the sandbar where you wade. Use the nearest station, read its time, and treat a reading older than a few hours as history, not news.
1998 waters with their own page
Every measured water has a page with all stations, trend and neighbours. The 30 with the most stations:
All 69 lakes in the directory · All 1244 rivers in the directory · All 685 beaches in the directory
How often are these US readings updated?
NOAA buoys typically report hourly, USGS river gauges every 15–60 minutes and state networks at their own pace. Right now the warmest measured US spot is Port O'Connor at 90 °F.
Are these measured or estimated temperatures?
Measured. Every value comes from a physical station and shows its measurement time. Where nothing measures, we say so instead of guessing.
What about beach water quality?
Over 250 US beaches carry their official EPA annual water-quality rating in the free BrrChecker app, alongside the temperature.
Check first, then drive.
Every US station with history, BrrScore and alerts, free in the app.
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