FZPQ50 PGUM 201901 SRFGUM Surf Zone Forecast for the Mariana Islands National Weather Service Tiyan GU 501 AM ChST Mon Sep 21 2026 .DISCUSSION...A moderate risk of rip currents will persist along west and south facing reefs through Tuesday, and along north and east facing reefs through Friday. A moderate risk of lightning will exist through Friday near Guam and Rota, and today plus Tuesday through Wednesday for Tinian and Saipan. $$ GUZ001-MPZ001>003-211015- Guam-Rota-Tinian-Saipan- 501 AM ChST Mon Sep 21 2026 36 hour Surf Zone Forecast for the Marianas from 600 AM Monday through 600 PM Tuesday .TODAY... Rip Current Risk.....Moderate *. Surf Height North facing reefs............4 to 6 feet. East facing reefs............4 to 6 feet. South facing reefs............3 to 5 feet. West facing reefs............3 to 5 feet. Swell/Period Primary swell................North at 2 to 4 feet. Primary period...............9 seconds. Secondary swell..............Northeast at 2 to 4 feet. Secondary period.............11 seconds. Tertiary swell...............Southwest at 2 to 3 feet. Tertiary period..............10 seconds. Water Temperature Pago buoy..........85 Degrees. Max Heat Index.........Around 104. Winds...............Southeast at 10 to 15 mph. .TONIGHT... Rip Current Risk.....Moderate *. Surf Height North facing reefs............3 to 5 feet. East facing reefs............3 to 5 feet. South facing reefs............3 to 5 feet. West facing reefs............3 to 5 feet. Swell/Period Primary swell................North at 2 to 4 feet. Primary period...............9 seconds. Secondary swell..............Northeast at 2 to 3 feet. Secondary period.............11 seconds. Tertiary swell...............Southwest at 2 to 3 feet. Tertiary period..............10 seconds. Winds...............South at around 10 mph. .TUESDAY... Rip Current Risk.....Moderate *. Surf Height North facing reefs............3 to 5 feet. East facing reefs............3 to 5 feet. South facing reefs............3 to 5 feet. West facing reefs............3 to 5 feet. Swell/Period Primary swell................North at 3 feet. Primary period...............8 seconds. Secondary swell..............Northeast at around 3 feet. Secondary period.............10 seconds. Tertiary swell...............Southwest at 2 to 3 feet. Tertiary period..............10 seconds. Max Heat Index.........Around 102. Winds...............Southeast at 10 to 15 mph. Tide information for the next 36 hours... At Apra Harbor, Guam... Low tide 0.3 feet at 9:34 AM Monday High tide 2.1 feet at 5:29 PM Monday Low tide 1.5 feet at 10:50 PM Monday High tide 1.9 feet at 3:13 AM Tuesday Low tide 0.2 feet at 10:31 AM Tuesday High tide 2.1 feet at 6:00 PM Tuesday Low tide 1.4 feet at 11:28 PM Tuesday At Rota Island... Low tide 0.3 feet at 9:28 AM Monday High tide 1.9 feet at 5:26 PM Monday Low tide 1.4 feet at 10:44 PM Monday High tide 1.8 feet at 3:10 AM Tuesday Low tide 0.2 feet at 10:25 AM Tuesday High tide 2.0 feet at 5:57 PM Tuesday Low tide 1.3 feet at 11:22 PM Tuesday At Tinian Island... Low tide 0.1 feet at 9:11 AM Monday High tide 1.5 feet at 5:27 PM Monday Low tide 0.5 feet at 10:27 PM Monday High tide 1.4 feet at 3:11 AM Tuesday Low tide 0.1 feet at 10:08 AM Tuesday High tide 1.6 feet at 5:58 PM Tuesday Low tide 0.5 feet at 11:05 PM Tuesday At Tanapag Harbor, Saipan... Low tide 0.3 feet at 9:47 AM Monday High tide 1.9 feet at 5:50 PM Monday Low tide 1.5 feet at 10:41 PM Monday High tide 1.7 feet at 2:52 AM TuesdayLow tide 0.2 feet at 10:37 AM Tuesday High tide 1.9 feet at 6:15 PM Tuesday Low tide 1.4 feet at 11:15 PM Tuesday * Low Risk of rip currents - Strong currents can still occur near jetties and reef channels. Always have a flotation device with you in the water. Moderate Risk of rip currents - Wave conditions support stronger or more frequent rip currents. Always have a flotation device with you in the water. High Risk of rip currents - Large waves will produce strong rip currents, especially along narrow reefs and beaches. Rip currents will be life threatening. If caught in a rip current, swim parallel to the beach rather than against the current. $$