Bakersfield, located in the southern portion of California’s Central Valley, is known for its intense, arid summers where daily high temperatures routinely exceed 90 degrees Fahrenheit. The shift toward cooler weather is a welcome change for residents, marking an end to the prolonged heat and a transition into the region’s mild winter climate. This change is a rapid progression that generally begins in late October and becomes firmly established by the start of November.
Identifying the Transition Months
The sensation of “cold” in Bakersfield is relative, moving from summer’s sweltering conditions to a comfortable coolness that characterizes the autumn season. The most significant change in weather accelerates rapidly through October, setting the stage for the cooler period. While early October may still feel like an extension of summer, the later weeks introduce a distinct crispness, especially after sundown.
The need for a jacket often emerges for the first time in the morning hours toward the end of October. By mid-November, the cooling trend is fully underway, and residents typically turn on the home heater for the first time. This transition establishes a cool season that lasts approximately three months, from late November until late February.
Historical Temperature Data
Examining historical monthly averages provides the clearest picture of the cooling process in the region. October represents the initial descent from summer heat, with average high temperatures around 80 degrees Fahrenheit. The average low temperature for October is around 53 degrees Fahrenheit, indicating that mornings and evenings are already becoming quite mild.
The true drop in temperature occurs in November, where average conditions change dramatically. The average daily high temperature for November falls to about 67 degrees Fahrenheit, representing a 13-degree drop from the previous month. Nighttime temperatures follow suit, with the average low in November cooling to approximately 43 degrees Fahrenheit. These average temperatures firmly establish the beginning of the cooler season, often requiring a coat throughout the day.
The cooling trend culminates in December, which is historically the coldest month of the year for Bakersfield. The average high temperature during December is around 59 degrees Fahrenheit. The average low temperature settles near 38 degrees Fahrenheit, which is the lowest monthly average low of the year.
The Difference Between Day and Night
A defining characteristic of Bakersfield’s weather, even in the cooler months, is its high diurnal temperature variation—a large difference between daytime highs and nighttime lows. The city’s arid subtropical climate and location in the San Joaquin Valley allow for significant warming under the sun. While the average December low is near freezing, the average high still reaches nearly 60 degrees Fahrenheit.
This wide swing is due to the dry nature of the air, which holds less heat than humid air, allowing temperatures to drop quickly after sunset and rise rapidly once the sun is up. The geographical basin of the valley, surrounded by mountains, further contributes by trapping air and limiting moisture movement. This means the midday sun can feel pleasantly warm, making layers necessary for managing temperature shifts throughout the day.