New Orleans is a south-easterly coastal city and has a humid subtropical climate. Therefore, it has very changeable weather: it can be humid and very hot, experience large amounts of rain and is subject to tropical storms. Its proximity to the sea also increases humidity. It rains often, especially in January and June.
The average summer temperature is 30 °C whilst the average winter temperature is 13 °C.
For the most reasonable weather, visit in spring and summer but be prepared for a range of weather conditions.
Dress and plan accordingly.