Historical weather data, all-time temperature records, and monthly climate averages for East Islip, NY. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in East Islip sits right in that unpredictable shoulder season — historically, highs average just 53° with lows dipping to 38°. The date has swung wildly over 62 years of records, from a balmy 75° in 2010 to a bitter 26° low back in 1972. Nearly a coin flip on precipitation, so keep an umbrella handy.
East Islip's weather has real extremes for a Long Island suburb — a scorching 104° on July 3rd, 1966 and a brutal -14° on February 13th, 1967, less than a year apart. The wettest single day on record dropped an incredible 13.51 inches on August 13th, 2014, and a January 2022 storm buried the area under 23.5 inches of snow.
Summer is the sweet spot here, with highs peaking around 82-84° in mid-July before tapering off through fall. January and February are the coldest months, with average highs barely cracking 40°. August is the wettest stretch of the year, so if you're planning a visit, July offers the best combination of warmth and slightly drier conditions.