Fog in Islip, NY

daily fog outlook & 2016–2026 climatology
No fog signal in NWS guidance for the next 48 hours. dense fog (visibility under a mile) is rare here in August.forecast cycle 2026-08-16T00:00:00Z · page rebuilt daily · live layers below update hourly

Measured at Long Island MacArthur Airport (KISP). This station is in forecast verification — percentages publish when it clears the accuracy bar.

Measuring station

stationairportfog hours/yrforecast
KISPLong Island MacArthur Airport107 h/yrverifying

Fog is measured where instruments live — airports. Hours/yr = time below CAT I approach minima (visibility under ~½ mile or ceiling under 200 ft), the aviation definition of seriously dense fog.

When Islip fogs in

Fog here concentrates in February and December — about 107 hours in a typical year at KISP, usually lasting ~2 h once it forms. Hour-by-hour patterns, live conditions and the forecast strip live on the KISP station page.

Fog season

January: ~12 hJanFebruary: ~15 hFebMarch: ~14 hMarApril: ~10 hAprMay: ~12 hMayJune: ~12 hJunJuly: ~2 hJulAugust: ~0 hAugSeptember: ~3 hSepOctober: ~6 hOctNovember: ~5 hNovDecember: ~14 hDec
Fog season runs October through June, peaking in February; fog is mostly a 5 AM–8 AM phenomenon; typically thinning out by noon; a typical event lasts about 2 hours once it forms local time · 10-yr average

Machine access: data.json · llms.txt · forecast verification. Not for operational use.