Louisiana’s humid subtropical climate means the seasonal shift from summer warmth to winter chill is often prolonged and gradual, unlike the abrupt changes experienced in northern latitudes. While the perception of “cold” is subjective, for most residents, it means daytime temperatures require more than just a shirt and shorts. This article identifies the typical timing for this seasonal transition and the definitive marker of freezing temperatures across the state.
The Seasonal Transition: When Temperatures Begin to Fall
Consistent temperature drops often start in late October, though this initial change is frequently interrupted by a period known locally as a “second summer.” This temporary return to warmth can see temperatures briefly climb back into the 80s before true cold air masses push south. The definitive shift to noticeably cooler weather solidifies in November, marking the end of the state’s extended warm season.
During this transition, average daytime high temperatures across the state typically move from the low 80s to the low 70s, which is the point when light jackets become a daily necessity. For example, the average high temperature in New Orleans drops from around 81°F in October to 72°F in November. As November progresses, overnight lows often settle into the 50s, prompting residents to turn on heating for the first time.
Regional Differences in Louisiana’s Cold Season
Louisiana’s considerable north-south span means the timing of the seasonal transition varies significantly across its parishes. Northern regions, often called North Louisiana, experience the onset of consistent cool air much earlier than their coastal counterparts. This earlier cooling results from their greater distance from the temperature-moderating influence of the Gulf of Mexico.
In the northern parishes, sustained cooler air, with highs consistently in the 60s, may arrive as early as mid-October or early November. Conversely, southern and coastal parishes maintain higher average temperatures well into the season. These areas may not experience a consistent chill until late November or even December. During a significant cold front, northern parishes can see highs drop into the 40s, while coastal areas may still reach the mid-60s.
Tracking the First Freeze
The most definitive benchmark for the cold season is the first occurrence of 32°F, the freezing point of water. This first freeze is a practical marker, signaling the time to take necessary precautions, such as covering sensitive outdoor plants or preparing outdoor plumbing. The historical average for this event follows a clear north-to-south gradient across the state.
Northern Louisiana, due to its higher latitude, typically sees its first freeze event between early and mid-November. In contrast, coastal parishes and areas surrounding the Gulf of Mexico benefit from residual warmth, often delaying this event. For these southern regions, the first freeze may not occur until late November or even late December.