Last updated: June 24, 2025
In May, the average temperature in Grand Isle, United States hovers around 10°C (51°F). Expect a varied range, with minimums dipping to -4°C (26°F) and maximums reaching up to 31°C (88°F). Be prepared for wet weather, as you'll encounter approximately 97 mm (3.8 in) of precipitation spread over 14 days, and enjoy a high average humidity level of 82%.
In May in Grand Isle, the average temperature is 10°C (51°F). The maximum can reach 31°C (88°F) and the minimum can be as low as -4°C (26°F). This range of temperatures makes it essential for travelers to be prepared for both warm and cool weather conditions during their visit.
In Grand Isle in May, the total precipitation amount is 97 mm (3.8 in) spread over 14 days.
In Grand Isle in May humidity is 82%. With an average temperature of 10°C (51°F), this humidity feels like a damp chill that clings to your skin, making outdoor adventures less appealing and prompting travelers to seek cozy indoor activities or warm drinks to counter the brisk air.
In Grand Isle in May, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Grand Isle.
UV Risk Categories
Weather in Grand Isle varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Grand Isle, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -11°C (13°F) | 89 mm (3.5 inches) | 93% | low |
| February Weather | -9°C (15°F) | 74 mm (2.9 inches) | 92% | moderate |
| March Weather | -5°C (24°F) | 77 mm (3.0 inches) | 90% | moderate |
| April Weather | 3°C (37°F) | 119 mm (4.7 inches) | 87% | high |
| May Weather | 10°C (51°F) | 97 mm (3.8 inches) | 82% | very high |
| June Weather | 15°C (60°F) | 92 mm (3.6 inches) | 77% | very high |
| July Weather | 19°C (66°F) | 93 mm (3.7 inches) | 81% | very high |
| August Weather | 18°C (65°F) | 84 mm (3.3 inches) | 83% | very high |
| September Weather | 13°C (56°F) | 100 mm (3.9 inches) | 85% | high |
| October Weather | 7°C (45°F) | 121 mm (4.7 inches) | 87% | moderate |
| November Weather | -1°C (31°F) | 119 mm (4.7 inches) | 87% | moderate |
| December Weather | -8°C (18°F) | 102 mm (4.0 inches) | 90% | low |