Be prepared with the most accurate 10-day forecast for East Islip, NY with highs, lows, chance of precipitation from The Weather Channel and Weather.com. East Islip, NY Weather Forecast and Conditions - The Weather Channel | Weather.com East Islip, NY As of 12:39 pm EDT 70° Partly Cloudy Day 69° • Night 49° Watch: Best Time To. Hourly Weather - East Islip, NY asOfTime Wednesday, October 4 9:30 pm 64° 4% 9:45 pm 64° 4% 10:00 pm 64° 4% Clear feelsLike 64° windSSW 3 mph humidity 96% uvIndex uvIndexVal cloudCover 12%.