Birmingham is located in a hilly area of north-central Alabama in the foothills of the Appalachians about 300 miles inland from the Gulf of Mexico. There is a series of southwest to northeast valleys and ridges in the area.
The city is far enough inland to be protected from destructive tropical hurricanes, yet close enough that the Gulf has a pronounced modifying effect on the climate.
Although summers are long and hot, they are not generally excessively hot. On a typical mid-summer day, the temperature will be nearly 70 degrees at daybreak, approach 90 degrees at mid-day, and level off in the low 90s during the afternoon. It is not unusual for the temperature to remain below 100 degrees for several years in a row. However, every few years an extended heat wave will bring temperatures over 100 degrees. July is normally the hottest month but there is little difference from mid-June to mid-August. Rather persistent high humidity adds to the summer discomfort.
January is normally the coldest month but there is not much difference from mid-December to mid-February. Overall, winters are relatively mild. Even in cold spells, it is unusual for the temperature to remain below freezing all day. Sub-zero cold is extremely rare, occurring only a very few times in recorded history. Extremely low temperatures almost always occur under clear skies after a snowfall. Snowfall is erratic. Sometimes there is a two or three-year span with no measurable snow. On rare occasions, there may be a 2 to 4 inch snowstorm. The snow usually melts quickly. Even 1 or 2 inches of snow can effectively shut down this sunbelt city because of the hilly terrain, the wetness of the snow and the unfamiliarity of motorists driving on snow and ice.
Birmingham is blessed with abundant rainfall. It is fairly well distributed throughout the year. However, some of the wetter winter months, plus March and July, have twice the rainfall of October, the driest month. Summer rainfall is almost entirely from scattered afternoon and early evening thunderstorms. Serious droughts are rare and most dry spells are not severe.
The stormiest time of the year with the greatest risk of severe thunderstorms and tornadoes is in spring, especially in March and April.
In a normal year, the last 32 degree minimum temperature in the spring is in mid to late March and the first in autumn is in early November.