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

79°F

Slight Chance Rain Showers

A slight chance of rain showers between 11am and 2pm. Mostly sunny. High near 79, with temperatures falling to around 76 in the afternoon. Southwest wind 5 to 10 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Grand Isle

When	Temp	Forecast	Wind	Precip
Today	79°F	Slight Chance Rain Showers	5 to 10 mph SW	15%
Tonight	69°F	Partly Cloudy	5 mph NW	2%
Thursday	77°F	Sunny	5 mph NW	2%
Thursday Night	70°F	Partly Cloudy	0 to 10 mph W	5%
Friday	77°F	Partly Sunny	5 to 10 mph N	13%
Friday Night	66°F	Partly Cloudy	5 to 15 mph N	2%
Saturday	73°F	Mostly Sunny	10 to 15 mph NE	2%
Saturday Night	63°F	Partly Cloudy	10 to 15 mph NE	2%
Sunday	69°F	Slight Chance Rain Showers	10 to 15 mph N	15%
Sunday Night	61°F	Partly Cloudy	10 to 15 mph N	6%
Monday	70°F	Mostly Sunny	10 to 15 mph NE	7%
Monday Night	62°F	Partly Cloudy	10 mph NE	5%
Tuesday	71°F	Sunny	5 to 10 mph NE	6%
Tuesday Night	65°F	Partly Cloudy	5 mph NE	4%

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

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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 Nov 4, 2026.