Editing Dallas (section)

=== Climate ===
{{Main|Climate of Dallas}}

{{climate chart
|Dallas, Texas
|37.9|57.7|2.59
|41.9|62.0|2.78
|49.4|69.9|3.45
|56.8|77.4|3.15
|66.0|84.9|4.57
|73.8|92.7|3.83
|77.7|96.9|1.71
|77.4|97.1|2.19
|70.1|90.0|3.10
|58.7|79.5|4.79
|47.8|67.8|2.93
|39.8|59.2|3.23
|float=right
|clear=both
|units=imperial
|source=[[National Oceanic and Atmospheric Administration|NOAA]]<ref name="Dallas Weatherbox NOAA txt" />
}}

Dallas has a [[humid subtropical climate]] ([[Köppen climate classification]]: ''Cfa'', [[Trewartha climate classification|Trewartha]]: ''Cfhk'') characteristic of the [[Great Plains|Southern Plains]] of the United States. It also has both continental and tropical characteristics, characterized by a relatively wide annual temperature range for the latitude. Located at the lower end of [[Tornado Alley]], it is prone to extreme weather, tornadoes, and hailstorms.

Summers in Dallas are very hot with high humidity, although extended periods of dry weather often occur. July and August are typically the hottest months, with an average high of {{convert|96.0|°F|°C|0|lk=on}} and an average low of {{convert|76.7|°F|°C|0}}. Heat indices regularly surpass {{convert|105|°F|°C|0}} due to elevated humidity during the summer months, making the summer heat almost unbearable. The all-time record high is {{convert|113|°F|0}}, set on June 26 and 27, 1980 during the [[Heat Wave of 1980]] at nearby [[Dallas/Fort Worth International Airport]].<ref name="NOAA Online" /><ref name="NWS Records">{{cite web|url=http://www.srh.noaa.gov/fwd/?n=dgr8mxmn|title=Dallas/Fort Worth – All-Time Maximum and Minimum Temperatures|publisher=National Weather Service Fort Worth|access-date=December 5, 2011}}</ref>

Winters in Dallas are usually mild, with occasional cold spells. The average date of first frost is November 12, and the average date of last frost is March 12.<ref>"[https://www.weather.gov/fwd/d32info DFW – Freeze Summary]". ''National Weather Service''. Retrieved November 2, 2018.</ref> January is typically the coldest month, with an average daytime high of {{convert|56.8|°F|°C|0}} and an average nighttime low of {{convert|37.3|°F|°C|0}}. The normal daily average temperature in January is {{convert|47.0|°F|0}} but sharp swings in temperature can occur, as strong cold fronts known as "[[Texas Norther|Blue Norther]]s" pass through the Dallas region, forcing temperatures below the {{convert|40|°F|0}} mark for several days at a time and often between days with high temperatures above {{convert|80|°F|0}}. Snow accumulation is seen in the city in about 70% of winter seasons, and snowfall generally occurs 1–2 days out of the year for a seasonal average of {{convert|1.5|in|cm|0}}. Some areas in the region, however, receive more than that, while other areas receive negligible snowfall or none at all.<ref>[http://www.srh.noaa.gov/fwd/CLIMO/dfw/normals/dfwann.html DFW Climate]. Retrieved on March 26, 2006. {{webarchive |url=https://web.archive.org/web/20081010041657/http://www.srh.noaa.gov/fwd/CLIMO/dfw/normals/dfwann.html |date=October 10, 2008 }}</ref> The all-time record low temperature within the city is {{convert|-10|°F|°C|0}}, set on February 12, 1899 during the [[Great Blizzard of 1899]].<ref>{{Cite web |date=2024-11-01 |title=February 1899 |url=https://www.weather.gov/fwd/feb1899 |access-date=2024-11-01 |website=National Weather Service, Fort Worth}}</ref>  The temperature at nearby [[Dallas/Fort Worth International Airport]] reached {{convert|-2|°F|°C|0}} on February 16, 2021, during [[February 13–17, 2021 North American winter storm|the February 2021 North American winter storm]].

Spring and autumn are transitional seasons with moderate and pleasant weather. Vibrant [[wildflower]]s (such as the [[bluebonnet (plant)|bluebonnet]], [[Castilleja|Indian paintbrush]] and other [[flora (plants)|flora]]) bloom in spring and are planted around the highways throughout Texas.<ref>[http://www.dot.state.tx.us/ TXDOT] {{webarchive |url=https://web.archive.org/web/20070812041600/http://www.dot.state.tx.us/ |date=August 12, 2007 }} – [http://www.dot.state.tx.us/travel/flora_conditions.htm Wildflower and Fall Foliage] {{webarchive |url=https://web.archive.org/web/20070408190352/http://www.dot.state.tx.us/travel/flora_conditions.htm |date=April 8, 2007 }}</ref> Springtime weather can be [[severe weather|quite volatile]], but temperatures themselves are mild. Late spring to early summer also tends to be the most humid, with humidity levels frequently exceeding 75%. The weather in Dallas is also generally pleasant from late September to early December and on many winter days. Autumn often brings more storms and tornado threats, but they are usually fewer and less severe than in spring.
[[File:Dusk view of the skyline, Dallas, Texas LCCN2011631144.tif|thumb|right|[[Sunset]] in Downtown Dallas]]
Each spring, cold fronts moving south from the North collide with warm, humid air streaming in from the [[Gulf Coast]], leading to severe [[thunderstorm]]s with [[lightning]], torrents of rain, [[hail]], and occasionally, [[tornado]]es. Over time, tornadoes have probably been the most significant natural threat to the city, as it is near the heart of [[Tornado Alley]].

A few times each winter in Dallas, warm and humid air from the south will override cold, dry air, resulting in [[freezing rain]] or ice and causing disruptions in the city if the roads and highways become slick. Temperatures reaching {{convert|70|°F|0}} on average occur on at least four days each winter month. Dallas averages 26 annual nights at or below freezing,<ref name="NOAA Online">{{cite web|url = https://w2.weather.gov/climate/xmacis.php?wfo=fwd|title = NowData – NOAA Online Weather Data|publisher = [[National Oceanic and Atmospheric Administration]]|access-date = November 30, 2012|archive-date = May 14, 2021|archive-url = https://web.archive.org/web/20210514013416/https://w2.weather.gov/climate/xmacis.php?wfo=fwd|url-status = dead}}</ref> with the winter of 1999–2000 holding the record for the fewest freezing nights with 14. During this same span of 15 years,{{specify|date=August 2013}} the temperature in the region has only twice dropped below {{convert|15|°F|°C|0}}, though it will generally fall below {{convert|20|°F|0}} in most (67%) years.<ref name="NOAA Online" />

The [[USDA|U.S. Department of Agriculture]] places Dallas in [[USDA plant hardiness zone|Plant Hardiness Zone 8b]].<ref>{{cite web|url=http://www.plantmaps.com/interactive-texas-usda-plant-zone-hardiness-map.php |title=Texas USDA Hardiness Zone Map |access-date=November 28, 2010}}</ref><ref>{{cite web |first=Ramon |last=Jordan |url=http://www.usna.usda.gov/Hardzone/hzm-sm1.html |title=Plant Hardiness Zone Map: South-Midwest US |publisher=Usna.usda.gov |date=January 24, 2012 |access-date=May 11, 2013 |archive-date=May 14, 2013 |archive-url=https://web.archive.org/web/20130514085928/http://www.usna.usda.gov/Hardzone/hzm-sm1.html |url-status=dead }}</ref> However, mild winter temperatures in the past 15 to 20 years had encouraged the horticulture of more cold-sensitive plants such as ''[[Washingtonia filifera]]'' and ''[[Washingtonia robusta]]'' [[palm tree|palms]], nearly all of which died off during [[February 13–17, 2021 North American winter storm|the February 2021 North American winter storm]]. According to the [[American Lung Association]], Dallas has the 12th highest air pollution among U.S. cities, ranking it behind Los Angeles and [[Houston]].<ref>[http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=50752#graph6 Lungusa.com]. Retrieved on March 2, 2006. {{webarchive|url=https://web.archive.org/web/20090529071113/http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=50752 |date=May 29, 2009 }}</ref> Much of the air pollution in Dallas and the surrounding area comes from a hazardous materials incineration plant in the small town of [[Midlothian, Texas|Midlothian]] and from cement plants in neighboring [[Ellis County, Texas|Ellis County]].<ref>[http://www.downwindersatrisk.org/ Downwindersatrisk.org] – [http://www.downwindersatrisk.org/DownwindersAtRisk-MovingToMidlothian.htm Pollution in Midlothian]. Retrieved on April 17, 2006. {{webarchive |url=https://web.archive.org/web/20150810122236/http://www.downwindersatrisk.org/ |date=August 10, 2015 }}</ref>

The average daily low in Dallas is {{convert|57.4|°F|°C|0}}, and the average daily high is {{convert|76.9|°F|°C|0}}. Dallas receives approximately {{convert|39.1|in|mm|0}} of rain per year. The record snowfall for Dallas was {{convert|11.2|in|cm|0}} on February 11, 2010.

{{Dallas weatherbox}}