TL;DR FIRST
- Beach/water safety: STAY OUT along west and north facing reefs. High Surf Advisory + Rip Current Statement in effect until Thursday, 4 PM ChST — waves 9 to 11 feet, life-threatening rip currents.
- Heat: hot and humid. Heat index up to 98°F today, 78°F overnight. Drink water before you feel thirsty; shade at midday.
- Rain: scattered showers and thunderstorms tonight through Tuesday, 30 to 40% chance, brief heavy rain possible. Keep a bag with a dry shirt in the car.
- Typhoon or emergency threat: none. No tropical cyclone activity in the Marianas. The rough water is a monsoon pattern, not a storm.
THEN THE FULL BRIEF
Two alerts from NWS Tiyan Guam cover the CNMI: a High Surf Advisory and a Rip Current Statement, both in effect from 3:03 AM this morning until 4 PM ChST Thursday, August 13. Both cover Saipan, Tinian, Rota, and Guam — west and north facing reefs are getting hit hardest. Waves are expected to run 9 to 11 feet with strong rip currents that can pull even strong swimmers out to sea. The cause is a strong monsoon pattern, not a named system.
Today (Sunday) is partly sunny with a high near 85°F and a heat index (what the air actually feels like once humidity is factored in) as high as 98°F. West-southwest winds 20 to 30 mph with gusts to 40 mph. Isolated showers and thunderstorms through the day, then scattered activity tonight with a low around 78°F and gusts to 35 mph. Rainfall chances climb to 40% Sunday night.
Monday and Tuesday look the same — highs near 85°F, scattered showers and thunderstorms, gusts to 40 mph. Things ease Wednesday and beyond: highs around 86°F, shower chances drop to slight, winds back off to 15 to 25 mph. Nights hold at 78°F all week.
This is the kind of monsoon surge worth watching even without a typhoon. See the pinned Dolphin thread for the live conditions report and community updates: 🌀 Typhoon Dolphin — current conditions thread (Jul 30, 2026)
What to do today: stay out of the water on west and north facing beaches until Thursday; if you’re caught in a rip current (water pulling you away from shore), don’t fight it — relax, float, and swim parallel to the shoreline until the current releases you; drink water and take shade breaks; charge your phone tonight in case of a power blip from tonight’s thunderstorms; secure loose outdoor items — 40 mph gusts will move them.