Snow in New York City in May: Rare but Real

New Yorkers know their weather defies calendars. While May typically brings blooming trees and sidewalk cafes, the city's climatic history includes a handful of startling late-season snow events—reminders that meteorology doesn't respect Memorial Day weekend plans.

The Statistics

• Average last measurable snow: April 15 (Central Park)
• Average first measurable snow: November 15
• May snow frequency: ~once per decade (trace or measurable)
• Latest measurable snow on record: May 9, 2017 (2.5 inches)
• Latest trace snow: May 27, 1961

Notable May Snow Events

Why It Happens

Late-season snow requires a precise collision of ingredients:

1. Cold air mass: A deep trough in the jet stream dragging Canadian air southward
2. Moisture: Coastal storm (nor'easter) or Great Lakes system feeding precipitation
3. Timing: Overnight/early morning hours when temperatures bottom out
4. Surface conditions: Ground temps just cold enough for accumulation on grass/rooftops, though pavement often stays warm

May's stronger sun angle and warmer ground make accumulation difficult—most May "snow" is wet slush that melts on contact with roads.

Impact & Response

• Transportation: Minimal road impact; mainly delays from wet leaves/slush on parkways
• Vegetation: Greater risk—heavy wet snow damages fully leafed trees and blooming flowers
• Psychological: High. May snow violates seasonal expectations, generating viral social media moments

Climate Change Context

Paradoxically, a warming climate may increase late-season snow volatility. Arctic amplification weakens the jet stream, allowing deeper troughs to plunge south later into spring. However, overall snow season length and total accumulation are declining.

Bottom Line

May snow in NYC is a meteorological curiosity, not a seasonal expectation. If you're visiting in May, pack layers and a rain jacket—but leave the snow boots at home. Unless it's 2017. Then all bets are off.