Arkansas’s overall climate is classified as Humid Subtropical (Cfa) under the Köppen climate classification system. This designation indicates generally mild winters and hot summers, with precipitation occurring throughout the year. The state’s southern latitude and proximity to the Gulf of Mexico create a dynamic weather environment where four distinct seasons are recognizable.
Seasonal Temperature Patterns
The Arkansas climate features a full cycle of four seasons, though the lengths and intensities vary greatly throughout the year. Summers are characterized by long periods of heat, often feeling oppressive due to high moisture levels, typically lasting from late May through September. In July, the state’s warmest month, average daily high temperatures across central Arkansas hover around 93°F, with overnight lows settling near 73°F.
Winter is generally short and mild, with temperatures fluctuating significantly due to alternating air masses moving through the region. January high temperatures average around 51°F, and the average low temperature is near the freezing point at 32°F. Cold, dry air from Canada can periodically push south, causing brief but sometimes severe cold snaps where temperatures drop well below freezing.
The transitional seasons, spring and autumn, are often pleasant but relatively brief. Spring is marked by a rapid warming trend beginning in March, though the last freeze of the season can occasionally occur as late as mid-May. Fall brings the first tastes of cooler air in September, though temperatures in the 90s have been recorded well into November.
Regional Climatic Differences
Arkansas’s varied topography significantly influences local climate conditions, creating distinct microclimates across the state. The mountainous regions, including the Ozark and Ouachita Mountains in the northern and western portions, experience noticeably cooler temperatures than the lowlands. In the Ozark Plateau, the mean January temperature is approximately 35°F, and annual snowfall totals tend to be higher than elsewhere in the state.
These elevated areas have a slightly more moderate summer, with mean July temperatures in the high 70s. In contrast, the flatter, low-lying areas, such as the Mississippi Alluvial Plain and the Gulf Coastal Plain to the east and south, have the highest average temperatures. These regions are subject to more intense summer heat and higher humidity, with mean July temperatures often exceeding 82°F in the southern coastal plain.
The Ouachita Mountains stand out as the region that receives the highest amount of annual rainfall. This geographic division highlights how elevation and proximity to the Gulf of Mexico govern the local climate experience, with the south and east being warmer and the north and west being cooler.
Precipitation and Humidity Levels
Annual precipitation typically falls between 40 and 60 inches across the state. This high volume of moisture is generally well-distributed throughout the year, preventing extended dry periods. The spring months, particularly March through May, often represent a primary wet season, with May frequently recorded as the rainiest month.
High relative humidity is a direct consequence of the state’s proximity to the Gulf of Mexico. Warm, moisture-laden air flows northward, especially during the summer months. This high humidity significantly raises the heat index and makes hot temperatures feel more extreme.
Snowfall is a minor component of the annual precipitation totals, with the state averaging only about four to five inches per year. While snow is infrequent and rarely heavy across the southern lowlands, the northern half of the state, especially the higher elevations, sees more frequent and heavier snow events.
Severe Weather Occurrences
Arkansas is susceptible to severe weather hazards throughout the year. The spring season, generally from March through May, is the primary period for severe thunderstorms and tornadic activity. These powerful storms frequently produce large hail, damaging straight-line winds, and numerous tornadoes.
The threat of winter ice storms occurs when warm, moist air from the Gulf of Mexico rises over a shallow layer of cold air near the surface. This causes freezing rain that can accumulate on trees and power lines, leading to widespread power outages and infrastructure damage. While minor ice accumulations are common most winters, major ice storms happen every five to ten years.
Heavy precipitation, especially during the spring wet season, poses a significant risk of flooding. Both flash flooding and major river flooding are threats. Additionally, the remnants of tropical systems originating in the Gulf of Mexico can track inland, dumping large volumes of rain and occasionally spawning smaller tornadoes.