FPMY50 PGUM 210533 ZFPGUM Zone Forecast for Guam and the Northern Marianas National Weather Service Tiyan GU 333 PM ChST Tue Apr 21 2026 GUZ001-MPZ001>003-212130- Guam-Rota-Tinian-Saipan- 333 PM ChST Tue Apr 21 2026 .TONIGHT...Partly cloudy with isolated light showers. Northeast winds 10 to 15 mph. Lows around 77. Chance of showers 10 percent. .WEDNESDAY...Mostly sunny with isolated light showers. East winds 10 to 15 mph. Highs around 87. Chance of showers 10 percent. .WEDNESDAY NIGHT...Partly cloudy with isolated showers. East winds 10 to 15 mph. Lows around 77. Chance of showers 20 percent. .THURSDAY THROUGH FRIDAY...Partly cloudy with isolated showers. East winds 15 to 20 mph. Highs around 87. Lows around 77. Chance of showers 20 percent. .FRIDAY NIGHT THROUGH TUESDAY...Partly cloudy with a 20 percent chance of showers. Lows in the upper 70s. Highs in the upper 80s. $$