The USA, due to its
immense size and geographical diversity, has various climates in different
locations. The south and west regions tend to be warmer and dryer while the
north and east are more temperate with colder winters. Coastal regions are
naturally milder than inland areas away from large bodies of water. Mountainous
regions of higher altitude are colder and receive higher levels of
precipitation.
The USA can be
broken up into different climatic regions that stretch in bands across the
country, but to make this more digestible to the holiday-maker this guide will
stick to the following geographical regions.
West: Washington, Oregon, California, Idaho, Utah, Nevada
Southwest: Arizona, New Mexico, Texas, Oklahoma
Central: Montana, North Dakota, South Dakota,
Wyoming, Colorado,
Nebraska, Kansas
Midwest: Minnesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, Indiana, Ohio
South: Arkansas, Louisiana, Kentucky, Tennessee,
Mississippi, Alabama, West Virginia, Virginia, North Carolina, South Carolina,
Georgia, Florida
Northeast: Vermont, New Hampshire, Maine, Massachusetts,
Rhode Island, Connecticut, New Jersey,
Delaware, Maryland, District of Columbia
Alaska: link
Hawaii: link
West
USA
The Pacific northwest
coast of the USA
is the wettest part of the country receiving year-round drizzle, some storms
and fog in the summer. However, summers are usually mild to hot and drier than
the winters which are mild to cold. The Pacific southwest coast, California, receives
pleasant weather all year with long, hot summers and mild winters. The interior
western states are drier, partially desert, with greater extremes of
temperature.
Washington and Oregon
Washington and Oregon are
coastal states, split by the Cascade Mountains.
Western areas receive a temperate, marine climate while east of the mountains
the climate is dry.
Seattle in Washington and Portland in Oregon see quite dry summers with the
occasional thunderstorm and average high temperatures around the mid 20s in the
height of summer. Summertime on the coast is often plagued with a dense fog but
when this clears hours of sunshine are to be enjoyed. Spring and autumn see
average day time temperatures around 12 °C. The
winter sees average highs around 8°C and lows around 2°C.
Snow does not fall often in urban areas but has been known in December.
Precipitation is high from autumn to spring and sees the ski season starting in
November.
East of the Cascade Mountains
conditions are semi-arid. The Columbian River Plateau is the driest area with a
number of deserts.
California
Officially nicknamed the Golden
State due to the discovery of gold in
1968, arguments have been made for California
to steal Florida’s nickname, the Sunshine State. California
is famed for the hot weather of its south coast but the state experiences
hugely varied weather as it stretches from the north to the south of America and has
diverse topological features.
San Francisco, on the northern part of
the coast, receives fairly mild summers with high temperatures averaging around
20°C in July and August. Night times cool off to
around 13°C. The mild winters are only
around 7°C cooler than the summers. This
still has a high impact on tourism and most visitors stick to the summer
months, but the variation between the highs and low of the year are relatively
tiny. The northern parts of California
are generally much wetter than the south.
Los Angeles on the southern coast is hot all
year round with a sub-tropical climate. It has a dry season from May till
October with average highs between 20 and 30°C, the
peak being in August. The wet season from November to April is cooler with
average highs staying in the early 20s. Los
Angeles sees an average of 263 days of sunshine a
year.
To the east of California’s mountains lie its arid desert
regions. Coastal California
is not susceptible to tropical cyclones. Earthquakes are quite common around
the San Andreas Fault which runs right through
the state.
Idaho
Idaho receives a temperate climate with all four seasons
remaining distinct. Summers are very hot, seeing average highs around 30°C while winters are
devastatingly cold, sometimes dropping below 0°F, which is a -18°C.
The record low is an unthinkable -51°C.
The protection of mountains gives Boise and Lewiston longer summers
than the rest of the state.
Utah and Nevada
Two of the four desert
states, Utah and Nevada
are far from their primary water source, the Pacific Ocean, and protected by
Sierra Nevada, the Cascades and the Rocky Mountains;
they receive low levels of precipitation. Regional climate depends largely on
altitude, with lower altitudes seeing typical desert conditions and higher
elevations receiving more temperate climates. The desert terrain and lack of
water result in vast temperature differences from day to night.
Salt Lake City, in Utah, receives all four
seasons with the hot summers tempered by winds from the lake, and cold, snowy
winters with temperatures regularly dropping below 0°C.
Las Vegas sits
right in the middle of the Mojave Desert in Nevada. It receives almost 300 days of
sunshine year and minimal rainfall that falls in short storms, sometimes
causing flash floods. The height of the summer sees blistering daily averages
in the 40s with stifling nights in the 20s. Winters are short and mild with day
time temperatures bottoming in January at 15°C, and
night times dipping just below freezing.
Mountainous areas are much cooler. The Rockies receive a lot of snow and are famous for skiing.
Southwest
USA
The southwest is typically
hot and dry with more temperate climates to the northeast. Tornado Alley
stretches between the Rocky and Appalachian Mountains
in the east of this region and tornados cause havoc through spring and early
summer.
Arizona and New Mexico
The remaining two desert
states, Arizona and New Mexico, see much the same climate as Utah
and Nevada:
hot and dry. As stated above, regional climate depends largely on altitude,
with lower altitudes seeing typical desert conditions and higher elevations
receiving more temperate climates. From May till October is the monsoon season
during which flash-flooding is possible.
The most famous
geographical feature of the area, and one of the seven wonders of the natural
world, is the Grand Canyon. Cutting across
central and northern Arizona, the Grand Canyon is a great example of the extreme contrasts
between climates at different altitudes. Its south rim is 1000 feet higher than
its north rim and sees snowy winters and warm summers around 20°C with cool nights
while the north rim sees ice and snow all year round. The inner canyon, deep
below the rim, sees summer highs nearing the 40s and night times do not cool
off so drastically.
Texas
Texas’s great size means it straddles a number of
climatic regions, but it is generally hot and dry in the summer and mild to cold in the
winter. The Texas High Plains on the New Mexican border are semi-arid and
desert-like. The mountains on the Mexican border see much cooler weather but
lower south arid conditions return. The rest of Texas is mostly sub-tropical, getting milder
towards the coast.
In Austin summer highs average around 36°C while winter sees misleading highs around
16°C; it can often be much colder. Houston is similar though slightly
milder with average summer highs around 34°C and winter highs around 17°C. Rainfall is always low.
Coastal Texas
is prone to hurricanes and the north contains the end of Tornado Alley.
Tornados usually occur in spring and early summer.
Oklahoma
Oklahoma is a temperate state receiving a continental
climate. It receives long, hot, dry summers and cold, snowy winters. The east
of the state is influenced by the humid, sub-tropical climate blown up from the
Gulf of Mexico. To the west conditions become
increasingly more arid. Oklahoma City, sitting
in gentle prairie land, is one of the sunniest and windiest cities in the USA. Most of Oklahoma is part of
Tornado Alley and the state is visited by numerous tornados, mostly between
April and June.
Central USA
The central states have a
temperate continental climate with four distinct seasons.
Montana, Wyoming
and Colorado
Although Montana
is considered part of the Great Plains, it has
many mountains. The Rockies, and the continental divide, stretch through
western Montana, right through Wyoming and Colorado.
The mountains restrict the flow of cool air from the east to the west, and warm
air from west to east. The Rockies have
unpredictable weather from day to day though the four seasons are very
distinct. Summers are warm and dry, interrupted by thunderstorms. Snow starts
falling in the autumn and sees the start of a long ski season though the best
of the ski season is seen to be in spring. Winter sport enthusiasts come from
all over the world to ski in Colorado’s
famed resorts such as Vale and Beaver Creek. The winter sees deep snow and
regular blizzards with temperatures falling at night to around a bitter -37°C. Spring is very changeable with
wet weather and increasing temperatures seeing the snow gradually melt away.
East of the mountains
weather is warmer with summers getting hotter the further south across the
three states. It is usually quite dry. Winters are extremely cold.
North Dakota and South Dakota
The Dakotas
receive a temperate climate with four distinct seasons. Summers are hot and dry
with periods of drought. The winters are bitingly cold.
Kansas and Nebraska
Both states receive continental
climates with distinct seasons. Summers are hot and winters are cold. The western
regions are dry and windy. The east is much more humid and receives the
majority of the states’ rain. This falls mostly in spring and summer and which
is when Kansas,
famously part of Tornado Alley, sees the majority of its tornados.
Summer in Kansas City is sweltering, seeing average
highs in the mid 30s with humidity at uncomfortable levels. The sun stays out
for around eleven hours a day and the nights provide little respite from the
heat. Spring and autumn see dramatic changes in temperature, quickly heating up
from 12°C in April to 18°C in May, and dropping from 20°C in October to 12°C in November. Night times are
considerable cooler. Winter months are very cold with day times lingering
between 1°C and
6°C, and
night times falling well below zero.
Midwest USA
The Midwest
is known for being hot and humid though it does receive all four seasons.
Minnesota, Iowa and Wisconsin
These states have typical
humid continental climates, enduring extremes of temperatures in the summer and
winter months. Lakes Michigan and Superior in Wisconsin
have some moderating effects on the surrounding areas. The Mississippi River
starts in Minnesota from Lake
Itasca and stretches all the way across
the USA to the Gulf of Mexico. It often creates state borders as it does
in the case of these three states. The Mississippi
and the lakes in the surrounding areas are a real draw for water sport lovers.
Waterskiing was invented on the stretch of the Mississippi
between Minnesota and Wisconsin
known as Lake Pepin.
The whole area is prone to
heavy precipitation seeing lots of snow in the winter and heavy rain in the
spring and summer. Thunderstorms are a regular occurrence, tornadoes are not
rare and the Mississippi
is susceptible to flooding. However, summer months still see a lot of sunshine
and the hot temperatures and beautiful waters draw many visitors.
Michigan
Michigan also has a humid continental climate for the most
part, but the Upper Peninsula and the northern part of the Lower
Peninsula receive much colder weather. They see warm, short
summers and long, upsettingly cold winters. January and February often see
average highs below freezing. The state is prone to violent thunderstorms and
tornadoes which are more frequent in the southern region.
Missouri, Illinois, Indiana and Ohio
These states also have
humid continental climates apart from their most southerly regions where the
climate is humid sub-tropical. While the majority of theses states receive the
typical blazing hot, humid summers and snowy, cold winters, the southern parts
receive milder winters. Thunderstorms are common in all states; Indiana sees some tornado activity and earthquakes are
not unheard of in Ohio.
The Missouri River is prone to heavy flooding.
July and August in Chicago in Illinois
are beautifully hot months, seeing an average high around 28°C. January, the coldest month,
sees average lows of -8°C with
regular snow.
South USA
The southern states are
typically hot in the summer with mild winters. The whole area is prone to
thunderstorms and coastal regions are sometimes hit by hurricanes.
Arkansas, Kentucky, Tennessee, West Virginia, Virginia
and North Carolina
These states enjoy a humid
sub-tropical climate receiving all four seasons with hot summers and mild
winters. There are many regional variations, mainly due to the Blue Ridge
section of the Appalachian Mountains which stretch across all of these states
apart from Kentucky.
In these areas higher elevation correlates with cooler temperatures and
increased snowfall in winter months. West Virginia, which is very mountainous, is one of the
wettest and cloudiest states in the USA. North Carolina is actually the wettest of
the eastern states due to the rain bearing southerly winds that come over the
mountains. However, in all of these states where rainfall is highest through
spring and summer, sunshine regularly follows the heavy downpours.
Kentucky and Tennessee
are far enough west, away from the ocean, to be safe from hurricanes, but
tornados are a risk. Virginia and North Carolina’s
Atlantic coast means they are susceptible to hurricanes that often do damage
far in land.
Virginia Beach, on Virginia’s coast right on the border with North Carolina, sees
average highs reaching just into the 30s in July and August. Wintertime sees
averages staying above freezing though it can dip below and while snow is rare,
it has been known to happen. This city is spared the majority of hurricanes as
their usual path is to the north.
Louisiana, Mississippi, Alabama, Georgia and South Carolina
The states of the Deep
South also have a pleasant humid sub-tropical climate with the southern parts
of the states, and all of Louisiana, with
coasts on the Gulf of Mexico, experiencing
higher temperatures year round. Northern regions are especially cooler in the
Appalachian Mountains which reach into Alabama,
Georgia and South Carolina.
Thunderstorms are common and there is the risk of hurricanes in the summer and
autumn months. Spring and autumn are warm with day time temperatures sometimes
reaching up into the 20s. Summers are long and hot, seeing daily average highs
in the mid 30s. Winters can get down to freezing but snow is rare, apart from
in the mountains. Rainfall is quite high all year round with the majority
falling in the summer months in thunderstorms.
New Orleans, on the coast of Louisiana, has been identified as one of the three cities
in America
most susceptible to hurricanes.
Florida
Most of Florida also has a humid sub-tropical
climate, usually warmer than the states to its immediate north. But closer to
Lake Okeechobee the weather quickly increases in heat and south of Lake
Okeechobee Florida
experiences a true tropical climate.
Jacksonville in the north of Florida
shares its summer temperatures with Miami
in the south, seeing summer average highs around 33°C. However, Jacksonville
is much colder in the autumn, spring and winter, seeing average lows of 6°C in January.
Miami ’s
tropical climate means warm to hot temperatures year round. It has hot, humid
summers with the monsoon season falling between May and October, and a warm,
dry winter. January, the coolest month, sees average highs of 24°C and
average lows of 16°C. Miami
is statistically the most like city in America to be hit by a hurricane.
Northeast
USA
The north-eastern states
are known for their pleasantly hot summers and snowy winters.
Maryland and Delaware
These states lie in the
transition zone between a humid sub-tropical climate and a continental climate
and as such have regional variations in weather. The southern regions of both
states receive humid sub-tropical conditions. While the whole region enjoys
long, hot summers, the northern areas see longer and colder winters. The east
of Maryland and most of Delaware are part of the flat Atlantic
Coastal plain. In the northern regions of Maryland
the flat land meets the Appalachian Mountains
which see heavy snow and temperatures below -12°C every winter. The states are surrounded by water:
Chesapeake Bay in the west, Delaware Bay in the east and the Atlantic
Ocean to the northeast. The states’ climates are moderated
somewhat by the abundance of water and coastal winds. Hurricanes are possible
though North Carolina,
to the south, provides protection from the majority of these tropical cyclones.
The District
of Columbia, Washington D.C., is surrounded by Maryland
apart from its southwest border which is with Virginia. It falls in the area’s humid
sub-tropical climate. Scorching summers see 30°C average highs in July and August with high levels of humidity keeping
temperatures up in the 20s at night and producing impressive electrical storms.
At this time of year the Potomac River is
prone to flooding which can cause extensive damage. In the winter average highs
around 7°C fall
to -3°C lows
at night and snow is to be expected.
Pennsylvania and New Jersey
These states also lie
somewhat in a transitional climate zone. Their north-western regions lie in the
humid continental zone with areas near their Maryland
and Delaware
borders, and on the coast, presenting features of the humid sub-tropical zone. Generally,
both states receive hot, muggy summers with high rainfall and mild to cool
winters with some snow.
Philadelphia is situated in the southeast of Pennsylvania in the humid sub-tropical zone.
It sees average highs up to the 30°C
in the height of the summer and average lows of -4°C in the winter with moderate snow. Newark,
in the northeast of New Jersey, also falls
just in the humid sub-tropical zone, but being that bit further north than Philadelphia sees average
temperatures infinitesimally lower than the southerly city with greater
snowfall in the winter.
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