Geography

Looking west, a view of Huntsville from atop Chapman Mountain. From south to north (left to right), Downtown Huntsville, Interstate 565, U.S. Space & Rocket Center, the Madison County Jail, University Drive, and Memorial Parkway are all visible.

Huntsville is located at 34°42′N 86°35′W / 34.700°N 86.583°W / 34.700; -86.583 (34.7, -86.6). The city has a total area of 210.0 square miles (543.9 km2). Huntsville has grown through recent annexations west into Limestone County, a total of 21.5 square miles (56 km2), or 13,885 acres (5,619.1 ha).

Situated in the Tennessee River valley, several plateaus and large hills partially surround Huntsville. These plateaus are associated with the Cumberland Plateau, and are locally called "mountains". Monte Sano Mountain (Italian for "Healthy Mount") is the most notable, and is east of the city along with Round Top (Burritt), Chapman, Huntsville, and Green mountains. Others are Wade Mountain to the north, Rainbow Mountain to the west, and Weeden and Madkin mountains on Redstone Arsenal in the south. Brindley Mountain is visible in the south across the Tennessee River.

As with other areas along the Cumberland Plateau, the land around Huntsville is karst in nature. The city was founded around the Big Spring, which is a typical karst spring, and many caves perforate the limestone bedrock underneath the surface, as is common in karst areas. The headquarters of the National Speleological Society are located in Huntsville.

Boundaries

The city is primarily surrounded by unincorporated land; the following incorporated areas border parts of the city:

Athens (far northwestern tip of Huntsville) Decatur (southwest) Owens Cross Roads (southeast) Triana (south)

The Huntsville city limits expanded west to wrap around and in 2011 fully surround the neighboring city of Madison.

Madison

Several unincorporated communities also border Huntsville, including:

Harvest (northwest) Meridianville (north) Moores Mill (northeast) Redstone Arsenal (U.S. Army base) (south) Climate A view of South Huntsville from atop Monte Sano Mountain

Huntsville has a humid subtropical climate (Köppen climate classification Cfa). It experiences hot, humid summers and generally mild winters, with average high temperatures ranging from 89.4 °F (31.9 °C) in the summer to 48.9 °F (9.4 °C) during winter.

Much of Huntsville's precipitation is delivered by thunderstorms. There are, on average, about 60 days per year during which thunder is reported. Thunderstorms are most frequent during the summer but the most severe storms occur during the spring and - sometimes - fall. These storms can deliver large hail, damaging straight line winds and tornadoes. Huntsville lies in a region of the country which is colloquially known as Dixie Alley, an area more prone to violent, long track tornadoes than most other parts of the US.

On April 27, 2011, one of the largest tornado outbreaks in history, the April 25–28, 2011 tornado outbreak, affected the Northern Alabama Area. During this event, an EF5 tornado that tracked near the Browns Ferry Nuclear Power Plant destroyed many transmission towers and caused a multi-day power outage for the majority of North Alabama. Significant Damage from that same tornado was also taken in the Anderson Hills subdivision and in Harvest, Alabama. In total, nine people were killed in Madison County alone and many others injured. Other significant tornado events include the Super Outbreak in 1974, the November 1989 Tornado Outbreak that killed 21 and injured almost 500, and the Anderson Hills Tornado that killed one and caused extensive damage in 1995. On January 21, 2010, Huntsville experienced a rare mid-winter tornado. It registered EF2 on the Enhanced Fujita scale scale and did only moderate damage but received extensive media coverage as it was not rain-wrapped and thus easily photographed.

Since Huntsville is nearly 300 miles (480 km) inland, hurricanes are rarely experienced with their full force; however, many weakened tropical storms cross the area after a U.S. Gulf Coast landfall. While most winters have some measurable snow, significant snow is rare in Huntsville; but there have been some anomalies, like the 1963 New Year's Eve snowstorm, when 17 in (43 cm) fell within 24 hours. Likewise, the Blizzard of 1993 and a Groundhog Day snowstorm in 1996 were substantial winter events for Huntsville. On Christmas Day 2010 Huntville recorded over 4 inches (100 mm) of snow in place, and on January 9–10, 2011 Huntsville 8.9 inches (230 mm) at the airport to over 10 inches (250 mm) in the suburbs.

Climate data for Huntsville, Alabama (1981–2010 normals) Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Record high °F (°C) 79 (26) 83 (28) 88 (31) 92 (33) 96 (36) 106 (41) 111 (44) 105 (41) 101 (38) 95 (35) 84 (29) 79 (26) 111 (44) Average high °F (°C) 50.1 (10.1) 54.9 (12.7) 63.8 (17.7) 72.6 (22.6) 80.3 (26.8) 87.2 (30.7) 89.7 (32.1) 89.9 (32.2) 84.0 (28.9) 73.6 (23.1) 62.7 (17.1) 52.5 (11.4) 71.8 (22.1) Average low °F (°C) 31.0 (−0.6) 34.7 (1.5) 41.5 (5.3) 49.3 (9.6) 58.6 (14.8) 66.4 (19.1) 69.7 (20.9) 68.6 (20.3) 61.7 (16.5) 50.2 (10.1) 41.0 (5) 33.7 (0.9) 50.5 (10.3) Record low °F (°C) −11 (−24) 1 (−17) 6 (−14) 25 (−4) 32 (0) 45 (7) 49 (9) 51 (11) 37 (3) 23 (−5) 1 (−17) −3 (−19) −11 (−24) Precipitation inches (mm) 4.88 (124) 4.83 (122.7) 5.20 (132.1) 4.31 (109.5) 5.10 (129.5) 4.29 (109) 4.04 (102.6) 3.60 (91.4) 3.72 (94.5) 3.59 (91.2) 4.94 (125.5) 5.77 (146.6) 54.29 (1,379) Snowfall inches (cm) 1.3 (3.3) 0.6 (1.5) 0.3 (0.8) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0.2 (0.5) 2.4 (6.1) Avg. precipitation days (≥ 0.01 in) 10.7 10.4 10.6 10.1 10.2 10.1 10.5 8.5 7.5 7.7 9.4 10.8 116.4 Avg. snowy days (≥ 0.1 in) 0.9 0.6 0.3 0 0 0 0 0 0 0 0 0.4 2.2  % humidity 56.5 73.5 71.0 70.0 70.0 72.5 73.5 76.0 74.5 74.0 70.0 70.5 75.0 Source #1: NOAA Source #2: climate-zone.com