Overview of the climate of the U.S. state of Alabama
The state of
Alabama
is classified as
humid subtropical
(
Cfa
) under the
Koppen climate classification
.
[1]
The state's average annual temperature is 64 °F (18 °C). Temperatures tend to be warmer in the state's southern portion with its proximity to the
Gulf of Mexico
, while its northern portions, especially in the
Appalachian Mountains
in the northeast, tend to be slightly cooler.
[2]
Alabama generally has hot, humid summers and mild winters with copious precipitation throughout the year. The state receives an average of 56 inches (1,400 mm) of rainfall each year and experiences a lengthy growing season of up to 300 days in its southern portion.
[2]
Hailstorms
occur occasionally during the spring and summer here, but they are seldom destructive. Heavy
fogs
are rare, and they are confined chiefly to the coast.
Thunderstorms
also occur year-around. They are most common in the summer, but they are most commonly severe during the spring (i.e. March through May) and late autumn (i.e. November). That is when destructive winds and
tornadoes
occur frequently, especially in the northern and central parts of the state.
Central
and
northern
Alabama are squarely within
Dixie Alley
, the primary area in the U.S. outside the Southern Plains (i.e. the traditional
Tornado Alley
) with relatively high tornado risk. Alabama is ranked second in the U.S for the deadliest tornadoes.
Hurricanes
are quite common in the state, especially in the
southern part
. Major hurricanes occasionally strike the coast, such as
Hurricane Frederic
in September 1979 and
Hurricane Ivan
in September 2004; both storms resulted in significant to devastating damage in the
Mobile
area.
Temperature
[
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]
Summers in Alabama are among the hottest in the United States, with high temperatures averaging over 90 °F (32 °C) throughout the summer in many parts of the state. In the extreme south, summer's heat is tempered slightly by winds from the
Gulf of Mexico
which often blow inland by up to 10?15 miles. In parts of northern Alabama, the elevation above sea level similarly tempers the summer heat. In summer, average afternoon high temperatures are especially high in
Montgomery
and
Tuscaloosa
(both averaging 92 °F (33 °C) in July and August). The average nighttime humidity is highest in southwest Alabama, which results in the highest average (high plus low temperature) for reporting stations in the state. While afternoon highs in
Mobile
are slightly cooler than those in
Alabama's inland cities, the warm nights produced by proximity to the
Gulf of Mexico
results in the average annual temperature for Mobile being the highest in the state. Cool morning temperatures help keep the northeast highlands among the more temperate locations in the state and lowest in the northeast among the highlands. Thus at Mobile the annual mean is 67 °F (19 °C), the mean for the summer 81 °F (27 °C), and for the winter 52 °F (11 °C); and at
Valley Head
, in
DeKalb county
, the annual mean is 59 °F (15 °C), the mean for the summer 75 °F (24 °C), and for the winter 41 °F (5 °C). At Montgomery, in the central region, the average annual temperature is 66 °F (19 °C), with a winter average of 49 °F (9 °C), and a summer average of 81 °F (27 °C). The average winter minimum for the entire state is 35 °F (2 °C), and there is an average of 35 days in each year in which the thermometer falls below the freezing-point. At extremely rare intervals the thermometer has fallen below 0 °F (?18 °C), as was the case in the extreme cold wave of 12?13 February 1899, when an absolute minimum of ?17 °F (?27 °C) was registered at Valley Head. The highest temperature ever recorded was 112 °F (44 °C) in
Centreville
, on September 6, 1925 (
https://www.ncdc.noaa.gov/extremes/scec/records
). During the exceptional August 2007 heat wave, three instances of official 108 °F (42 °C) heat were recorded at Maxwell AFB in Montgomery, each tying the all-time record for the capital city. Winters are generally mild in Alabama, as they are throughout most of the
southeastern United States
, with average January low temperatures around 40 °F (4 °C) in Mobile, around 31 °F (?1 °C) in Huntsville, around 35 °F (2 °C) in Montgomery, and around 33 °F (1 °C) in Birmingham.
Monthly normal high and low temperatures for various Alabama cities [°F (°C)]
Month
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
Year
|
|
Huntsville
[3]
|
Average high
|
48.9
(9.4)
|
54.6
(12.6)
|
63.4
(17.4)
|
72.3
(22.4)
|
79.6
(26.4)
|
86.5
(30.3)
|
89.4
(31.9)
|
89.0
(31.7)
|
83.0
(28.3)
|
72.9
(22.7)
|
61.6
(16.4)
|
52.4
(11.3)
|
71.1
(21.7)
|
Average low
|
30.7
(-0.7)
|
34.0
(1.1)
|
41.2
(5.1)
|
48.4
(9.1)
|
57.5
(14.2)
|
65.4
(18.6)
|
69.5
(20.8)
|
68.1
(20.1)
|
61.7
(16.5)
|
49.6
(9.8)
|
40.7
(4.8)
|
33.8
(1.0)
|
50.1
(10.1)
|
Birmingham
[4]
|
Average high
|
52.8
(11.6)
|
58.3
(14.6)
|
66.5
(19.2)
|
74.1
(23.4)
|
81.0
(27.2)
|
87.5
(30.8)
|
90.6
(32.6)
|
90.2
(32.3)
|
84.6
(29.2)
|
74.9
(23.8)
|
64.5
(18.1)
|
56.0
(13.3)
|
73.4
(23.0)
|
Average low
|
32.3
(0.2)
|
35.4
(1.9)
|
42.4
(5.8)
|
48.4
(9.1)
|
57.6
(14.2)
|
65.4
(18.6)
|
69.7
(20.9)
|
68.9
(20.5)
|
63.0
(17.2)
|
50.9
(10.5)
|
41.8
(5.4)
|
35.2
(1.8)
|
50.9
(10.5)
|
Montgomery
[5]
|
Average high
|
57.6
(14.2)
|
62.4
(16.9)
|
70.5
(21.4)
|
77.5
(25.3)
|
84.6
(29.2)
|
90.6
(32.6)
|
92.7
(33.7)
|
92.2
(33.4)
|
87.7
(30.9)
|
78.7
(25.9)
|
68.7
(20.4)
|
60.3
(15.7)
|
77.0
(25.0)
|
Average low
|
35.5
(1.9)
|
38.6
(3.7)
|
45.4
(7.4)
|
52.1
(11.2)
|
60.1
(15.6)
|
67.3
(19.6)
|
70.9
(21.6)
|
70.1
(21.2)
|
64.9
(18.3)
|
52.2
(11.2)
|
43.5
(6.4)
|
37.6
(3.1)
|
53.2
(11.8)
|
Mobile
[6]
|
Average high
|
60.7
(15.9)
|
64.5
(18.1)
|
71.2
(21.8)
|
77.4
(25.2)
|
84.2
(29.0)
|
89.4
(31.9)
|
91.2
(32.9)
|
90.8
(32.7)
|
86.8
(30.4)
|
79.2
(26.2)
|
70.1
(21.2)
|
62.9
(17.2)
|
77.4
(25.2)
|
Average low
|
39.5
(4.2)
|
42.4
(5.8)
|
49.2
(9.6)
|
54.8
(12.7)
|
62.8
(17.1)
|
69.2
(20.7)
|
71.8
(22.1)
|
71.7
(22.0)
|
67.6
(19.8)
|
56.3
(13.5)
|
47.8
(8.8)
|
41.6
(5.3)
|
56.2
(13.4)
|
Extremes
[
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]
Climate data for Alabama
|
Month
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Jun
|
Jul
|
Aug
|
Sep
|
Oct
|
Nov
|
Dec
|
Year
|
Record high °F (°C)
|
88
(31)
|
89
(32)
|
94
(34)
|
98
(37)
|
105
(41)
|
109
(43)
|
111
(44)
|
109
(43)
|
112
(44)
|
103
(39)
|
92
(33)
|
88
(31)
|
112
(44)
|
Record low °F (°C)
|
?27
(?33)
|
?18
(?28)
|
2
(?17)
|
19
(?7)
|
29
(?2)
|
35
(2)
|
41
(5)
|
39
(4)
|
29
(?2)
|
19
(?7)
|
?2
(?19)
|
?10
(?23)
|
?27
(?33)
|
Source: ?
|
Precipitation
[
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]
The amount of precipitation is greatest along the coast (62 inches/1,574 mm) and evenly distributed through the rest of the state (about 52 inches/1,320 mm). Much of the rainfall is produced by thunderstorms and, occasionally, by hurricanes and other tropical disturbances. In central and northern Alabama, average monthly precipitation amounts are highest from November to April, typically peaking in December or March, as at
Huntsville
(December maximum) or
Birmingham
(March maximum), with August to October the driest months. Along the coast, summer thunderstorm rains are markedly more frequent and tropical weather systems are a threat from July to October. Accordingly, at
Mobile
, virtually the wettest city annually anywhere in the eastern United States (wetter than even
Miami, FL
with its drier winters), monthly average precipitation peaks in July and August, but virtually the entire year is wet, with October a slightly drier month.
Although snow is a rare event in much of Alabama, areas of the state north of Montgomery may receive a dusting of snow a few times every winter, with an occasional moderately heavy snowfall every few years. Historic heavy snowfall events include the
New Year's Eve 1963 snowstorm
and the
1993 Storm of the Century
. The annual average snowfall for the Birmingham area is 2 inches (51 mm) per year. In the southern Gulf coast, snowfall is less frequent, sometimes going several years without any snowfall.
El Nino and La Nina
[
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]
During
El Nino
, Alabama receives colder than average winter temperatures with wetter than average conditions along the southern parts of the state and drier than average conditions in the northern parts.
La Nina
brings warmer than average temperatures with the drier weather in the southern parts of the state due to a northern storm track.
Hazards
[
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]
Alabama is also prone to
tropical storms
and even
hurricanes
. Areas of the state far away from the Gulf are not immune to the effects of the storms, which often dump tremendous amounts of rain as they move inland and weaken.
[7]
Thunderstorms
are common during the summer throughout Alabama and also occur during other times of the year including winter. South Alabama reports many thunderstorms. The Gulf Coast, around Mobile Bay, averages between 100 and 110 days per year with thunder reported, which eastern and northwest Alabama have 70 to 80 thunderstorm days per year.
[8]
Occasionally, thunderstorms are severe with frequent
lightning
and large
hail
? the central and northern parts of the state are most vulnerable to this type of storm, the northern and central regions of Alabama are especially prone to tornadoes. Alabama ranks seventh in the number of deaths from lightning and ninth in the number of deaths from lightning strikes per capita.
[9]
Tornadoes
occur frequently in Alabama during the spring and fall months, these tornadoes can be devastating and even deadly.? these are common throughout the state, although the peak season for tornadoes varies from the northern to southern parts of the state. Alabama, along with
Kansas
, has more reported
F5
/
EF5 tornadoes
than any other state ? according to statistics from the
National Climatic Data Center
for the period January 1, 1950, to October 31, 2006. An F5 tornado is the most powerful of its kind.
[10]
Several long ? tracked F5 tornadoes have contributed to Alabama reporting more tornado fatalities than any other state except for
Texas
and
Mississippi
. The Super Outbreaks of
April 1974
and
April 2011
both badly affected Alabama. The northern part of the state ? along the Tennessee Valley ? is one of the areas in the US most vulnerable to violent tornadoes . The area of Alabama and Mississippi most affected by tornadoes is sometimes referred to as
Dixie Alley
, as distinct from the
Tornado Alley
of the Southern Plains. Alabama is one of the few places in the world that has a secondary
tornado season
(November and December) along with the spring severe weather season.
See also
[
edit
]
References
[
edit
]
- ^
Christopher M. Godfrey (November 4, 2008).
"Greenhouse effect and climate"
(PDF)
.
Atmospheric Sciences
. University of North Carolina, Asheville. Archived from
the original
(PDF)
on 19 July 2011.
- ^
a
b
"Alabama Climate"
. Britannica.com
. Retrieved
October 24,
2010
.
- ^
"Climatography of the United States No. 20 (1971?2000) - Huntsville Intl AP, AL"
(PDF)
.
National Oceanic and Atmospheric Administration
. 2004.
Archived
(PDF)
from the original on July 23, 2013
. Retrieved
July 6,
2011
.
- ^
"Climatography of the United States No. 20 (1971?2000) - Birmingham Intl AP, AL"
(PDF)
.
National Oceanic and Atmospheric Administration
. 2004.
Archived
(PDF)
from the original on July 23, 2013
. Retrieved
July 6,
2011
.
- ^
"Climatography of the United States No. 20 (1971?2000) - Montgomery Dannelly AP, AL"
(PDF)
.
National Oceanic and Atmospheric Administration
. 2004.
Archived
(PDF)
from the original on July 23, 2013
. Retrieved
July 6,
2011
.
- ^
"Climatography of the United States No. 20 (1971?2000) - Mobile Rgnl AP, AL"
(PDF)
.
National Oceanic and Atmospheric Administration
. 2004.
Archived
(PDF)
from the original on July 23, 2013
. Retrieved
July 6,
2011
.
- ^
David M. Roth (2011).
"Tropical Cyclone Rainfall for the Gulf Coast"
.
Hydrometeorological Prediction Center
. Retrieved
2011-02-11
.
- ^
Christopher C. Burt, Mark Stroud (2007).
Extreme weather: a guide & record book
. W. W. Norton & Company. p.
138
.
ISBN
978-0-393-33015-1
.
- ^
National Lightning Safety Institute (2004-05-29).
"Lightning Fatalities, Injuries, and Damage Reports in the United States"
. Archived from
the original
on 2012-10-22
. Retrieved
2011-02-11
.
- ^
Fujita scale
Archived
December 30, 2011, at the
Wayback Machine
. Tornadoproject.com. Retrieved September 3, 2007.