May 22, 2026 · Updated May 22, 2026
Long Island's Memorial Day weekend opens with rain arriving Saturday morning and tracking through Sunday, with totals near one to two inches possible before skies improve in time for a mostly dry Monday. Temperatures recover to the low 70s by Memorial Day, with an above-average heat surge expected inland through midweek.
Rain moves into Long Island Saturday morning and tracks through much of the holiday weekend, but the pattern breaks in time for Memorial Day itself: Monday looks mostly dry, with clearing skies and temperatures near 73 degrees by afternoon across the South Shore.
The holiday weekend arrives as Long Island transitions out of a brief warm stretch that pushed inland temperatures into the low 80s earlier this week. Warm, moist air drawn north is now colliding with a cooler system dropping in from the northwest. The collision produces the rain event forecasters have been advertising since Wednesday. Current models put rainfall totals at one to two inches, with the heaviest amounts arriving Saturday afternoon and in the early hours of Sunday morning.
Friday, May 22: The cleanest day of the stretch. Partly sunny, highs in the upper 60s. No rain expected until after dark. If you have outdoor prep to do before the weekend, Friday afternoon is the window.
Saturday, May 23: Rain develops Saturday morning, likely arriving between 7 and 10 a.m. across western Nassau and moving east through the morning hours. Conditions worsen through the afternoon, with the heaviest rain in the evening. Highs stay around 62 degrees. Events scheduled for Saturday at Old Bethpage Restoration Village and the American Airpower Museum in Farmingdale may be affected; check those venues directly for weather-related updates.
Sunday, May 24: The front pushes through overnight Saturday into early Sunday. Rain may still be falling when the day begins, but conditions should improve through Sunday morning as the system moves east. Scattered showers remain possible through the afternoon. The Cedarhurst-Lawrence Five Towns Memorial Day Parade, which steps off at 10 a.m. Sunday, has a reasonable window if the heaviest rain passes by then — but uncertainty remains. Highs recover to the mid-60s.
Monday, May 25 — Memorial Day: The best day of the three. Mostly cloudy with periods of clearing, a few passing showers possible but no significant rain. Highs near 73 degrees across the South Shore; inland communities like Farmingdale, Mineola and Medford may push closer to 76 or 77. Most of the island's Memorial Day parades step off between 9:30 and 11 a.m., landing in the improved part of the forecast.
The rain system clears by Monday evening, and what follows is a notable early-summer warmup. Temperatures are expected to climb Tuesday and Wednesday, with inland areas reaching the mid-to-upper 80s by midweek. South Shore communities near the ocean stay cooler: water temperatures off Jones Beach and Fire Island's Atlantic shore are still in the upper 50s in late May, keeping waterfront towns five to eight degrees below inland readings. A day that reaches 87 degrees in Hauppauge might top out at 80 in Bay Shore or 78 in Babylon Village.
A mid-80s stretch in late May runs roughly 13 degrees above average for Long Island. The normal high for this period at Islip MacArthur Airport is around 70 to 72 degrees. Readings in the mid-80s next week would feel like mid-July on a South Shore beach, cold-water temperatures notwithstanding.
Long Island's ocean beaches open for supervised swimming Memorial Day weekend, when lifeguards take their chairs at Jones Beach State Park, Robert Moses State Park and most town and village beaches. Water temperatures — typically 58 to 62 degrees at Atlantic-facing beaches in late May — mean most swimming is for the genuinely cold-tolerant. The beaches are fully open for walking, sitting and watching, and a 73-degree Monday with partial sun is reasonable for all of that.
Bay and sound beaches along the Great South Bay, Long Island Sound and Peconic Bay warm faster than ocean beaches in spring. The bay-side beaches of Fire Island, accessible by ferry from Bay Shore and Sayville, typically run five to 10 degrees warmer than the ocean by late May. For families with young children who want to wade in water that does not hurt, bay-side is the call this Memorial Day.
State parks charge entrance fees beginning Memorial Day weekend. Jones Beach charges $10 per vehicle for Nassau County residents and $20 for out-of-county vehicles on peak days. Robert Moses State Park, accessible from Bay Shore and Babylon via the Robert Moses Causeway, runs similar rates. Arrive by 9:30 a.m. on any clear summer day or the main lots fill well before noon.
Long Island's east-west orientation and ocean exposure create a weather pattern distinct from mainland New York. The island sits in the path of systems moving northeast off the mid-Atlantic coast, meaning late May storms often arrive wetter than regional forecasts for the broader metro area suggest. The Atlantic moderates temperature extremes year-round, creating a seasonal lag: Long Island heats more slowly in spring and cools more slowly in fall than areas 50 miles to the north.
This matters most for Memorial Day beach trips. A 73-degree afternoon in Nassau County feels comfortable until you are standing on a windward barrier beach where the ocean is 59 degrees and a 15-mile-per-hour sea breeze is cutting in off the water. The standard Long Island late-May dress code is jeans and a sweatshirt for the beach, shorts if you end up somewhere inland by afternoon. Layers are useful through the first weeks of June.
The North Fork and South Fork also behave differently from the South Shore. Riverhead and Greenport tend to track closer to interior Connecticut in their weather patterns. Montauk, at the island's eastern tip, stays warmer than the mainland in winter and cooler than Nassau in summer, both effects of near-total ocean exposure. Knowing which end of the island you are headed to Monday helps calibrate what to pack.
Forecasts for five-day windows over the Northeast in late May carry meaningful uncertainty. If Monday does not improve as expected, Long Island has enough indoor options to make the holiday work. The American Airpower Museum at 1230 New Highway in Farmingdale runs its programs in hangars, with static aircraft displays sheltered from rain. The Long Island Children's Museum at 11 Davis Avenue in Garden City operates full programming on the holiday. The Cold Spring Harbor Whaling Museum at 301 Main Street in Cold Spring Harbor, which updated its exhibits this year, is open through the weekend.
The reliable read from this forecast: Saturday is the wet day, Monday is the good day, Sunday is uncertain. Plan the outdoor activities that matter most for Monday and build Saturday around options that can move indoors. If Monday delivers, the South Shore is yours.
