Harman US

Grand Isle, LA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Grand Isle, a town in Jefferson County, Louisiana.

Today
88°F
Slight Chance Showers And Thunderstorms then Sunny
A slight chance of showers and thunderstorms before noon. Sunny, with a high near 88. West wind around 5 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Grand Isle

WhenTempForecastWindPrecip
Today 88°F Slight Chance Showers And Thunderstorms then Sunny 5 mph W 20%
Tonight 82°F Mostly Clear 5 mph SW 4%
Wednesday 88°F Sunny 5 mph SW 14%
Wednesday Night 82°F Mostly Clear 5 mph S 3%
Thursday 88°F Sunny 0 to 5 mph S 9%
Thursday Night 81°F Mostly Clear 5 mph SE 9%
Friday 87°F Chance Showers And Thunderstorms 5 to 10 mph E 30%
Friday Night 82°F Partly Cloudy then Slight Chance Showers And Thunderstorms 5 mph E 21%
Saturday 87°F Chance Showers And Thunderstorms 5 to 10 mph E 42%
Saturday Night 82°F Slight Chance Showers And Thunderstorms 5 mph SE 22%
Sunday 87°F Chance Showers And Thunderstorms 5 mph SE 52%
Sunday Night 82°F Chance Showers And Thunderstorms 5 mph S 27%
Monday 87°F Chance Showers And Thunderstorms 5 mph S 45%
Monday Night 82°F Slight Chance Showers And Thunderstorms 5 to 10 mph S 19%

Forecast source: National Weather Service (api.weather.gov) for Grand Isle (29.213, -90.029). Updated through the day.

Growing snapshot for Grand Isle

Last spring frost
Feb 8
First fall frost
Dec 19
Growing season
311 days
Hardiness zone
10a

More local growing data for Grand Isle: nearby ZIP 70358 weather · frost dates · planting calendar · Louisiana frost dates

Nearby towns & communities

All Louisiana locations ›

Climate data from the nearest NOAA station, Galliano, La (24 mi from Grand Isle). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.