December in St. Augustine brings a distinct shift in atmosphere, transitioning the historic coastal town from the vibrant energy of late fall to the quiet charm of the winter season. While the summer heat fades, the city does not plunge into deep winter cold, instead settling into a period of mild, often pleasant days and cooler evenings. Understanding the specific temperature patterns, historical records, and what to expect on any given day is essential for visitors planning a getaway and for residents adjusting to the seasonal rhythm.
Average December Temperature Ranges
The typical temperature in St. Augustine during December falls into a comfortable and moderate range that defines the Florida winter experience. Daily high temperatures generally hover around the mid-60s Fahrenheit, specifically near 65°F (18°C). This represents a significant but not drastic drop from the fall averages, allowing for outdoor activities without the intense humidity of the summer months. Conversely, nightly low temperatures often dip into the upper 40s°F, averaging around 48°F (9°C), creating a crispness that necessitates a light jacket or sweater after sunset.
Daily Temperature Variability
Unlike the consistent, oppressive heat of a Florida summer, December weather introduces noticeable variability between morning, afternoon, and night. Mornings usually begin with the coolest air, with temperatures starting in the low 50s°F before the sun climbs higher. The afternoon sun provides substantial warmth, often pushing the mercury up 15 to 20 degrees from the morning chill. This daily swing means layering clothing is not just a stylistic choice but a practical necessity to remain comfortable throughout the day.
Historical Data and Records
Long-term climate data provides a reliable benchmark for what residents and visitors can expect. The historical average temperature for the month of December in St. Augustine is approximately 60.8°F (16°C). This figure is derived from decades of meticulous record-keeping and represents the midpoint between the frequent warm afternoons and the cooler overnight periods. While every year deviates from this average, it serves as a solid baseline for planning purposes.
When Temperatures Depart from the Norm
Although the averages provide a stable reference, December is capable of surprising with its extremes. Cold snaps originating from the northern United States can push temperatures into the low 40s°F or even upper 30s°F on rare occasions, accompanied by brisk winds that amplify the chill. Conversely, unseasonable warm spells, sometimes influenced by shifting atmospheric patterns, can send temperatures soaring into the low 80s°F (27°C). These outliers highlight the dynamic nature of Northeast Florida winter weather.
Precipitation and Its Relationship to Temperature
Temperature perception in St. Augustine is also intertwined with humidity and precipitation. December is generally one of the drier months in the region, with lower humidity levels contributing to a more pronounced coolness in the air. Rainfall is moderate, averaging around 2.5 inches for the month, spread across approximately 10 days. Because the air is often drier than the mug conditions of summer, the actual temperature feels less penetrating and more refreshing, even when the mercury dips.
What to Wear and How to Prepare
Packing for a December visit to St. Augustine requires a strategic approach to accommodate the shifting temperatures. Light to medium-weight clothing such as long-sleeve shirts and comfortable pants are ideal for the daytime. The key to comfort lies in the outer layers: a quality windbreaker or a light fleece jacket is essential for combating the breeze off the Intracoastal Waterway and the cooler evening air. Footwear should be comfortable for walking, as the historic brick streets can be uneven and the cooler weather encourages exploration without overheating.
