During the winter of 2023-2024, the United States experienced its warmest winter in nearly 130 years of recorded history. The Lower 48 states saw an average temperature of 37.6 degrees Fahrenheit, which is 5.4 degrees above the average. This significant deviation from the norm was attributed to a combination of long-term warming trends and the influence of El Nino.
Across the country, from Colorado to New Jersey and Texas to the Carolinas, signs of spring arrived three to four weeks earlier than the average over the past three decades. This early onset of spring was noted by the National Phenology Network, which tracks natural signs of the changing seasons.
The lack of winter was particularly striking in states like Vermont, Maine, and Michigan, where temperatures remained unusually mild. In fact, Michigan saw mosquitoes active in February, prompting concerns and even disaster loans for businesses affected by the absence of snow.
Experts pointed to human-caused climate change, driven by the burning of fossil fuels, as the primary factor behind the record warmth. The trend of rising temperatures has been consistent, with winters in the Lower 48 states now averaging 2.2 degrees warmer than in 1980.
While the warming trend continues, there have been fluctuations in the rate of temperature increase. Winter weather patterns have been affected by Arctic Amplification, which has disrupted the polar vortex and led to shifting weather patterns. This phenomenon has resulted in sporadic cold snaps but has not been sufficient to counteract the overall warming trend.
The consequences of the warm winter extend beyond temperature records. Early spring blooms can disrupt ecosystems, affecting pollinators and migratory birds. Additionally, warm winters can lead to longer and more severe pest seasons, as well as worsened allergy seasons due to increased pollen levels.
Despite the challenges posed by the warm winter, there is hope for regions like California, where atmospheric rivers and snowstorms are expected to replenish snowpacks and reservoirs. The unusual weather patterns observed during the winter of 2023-2024 serve as a stark reminder of the ongoing impacts of climate change on our environment.