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Real-time pollen data for Lewisville — updated daily.
Oak (post oak, blackjack oak, live oak, red oak) dominates the Cross Timbers woodland and is Lewisville's heaviest tree pollen producer, peaking March-April. Cedar elm and American elm produce substantial early spring pollen. Pecan peaks April-May. Hackberry, bois d'arc (Osage orange), and cottonwood are common Cross Timbers species. Ash, mulberry, and ornamental Bradford pear add significant spring pollen. Mesquite peaks May-June. Sycamore lines the Elm Fork Trinity River corridor. Pine (loblolly, slash) from residential plantings contributes.
While Lewisville lacks native Mountain cedar, pollen drift from the Hill Country and Cross Timbers cedar populations reaches clinically significant levels in the DFW area during winter. "Cedar fever" — severe sneezing, watery eyes, congestion, and fatigue — is a major winter allergen for North Texas residents. December through February is peak cedar drift season.
Bermuda grass dominates residential lawns, parks, and maintained landscapes. Native Blackland Prairie grasses — bluestem, switchgrass, Indian grass, sideoats grama — produce substantial spring pollen, especially from LLELA's restored prairie. Johnson grass is a major agricultural and roadside allergen. Perennial ryegrass and fescue are common in overseeded lawns. Grass pollen can be detected nearly year-round in Lewisville's mild winters.
Ragweed is the dominant fall allergen — North Texas is one of the highest ragweed-concentration regions in the United States. Pigweed (amaranth), lamb's quarters, dock, and plantain produce substantial pollen. Sagebrush and marsh elder are common. Goldenrod is often blamed but is insect-pollinated and rarely allergenic.
Lewisville Lake's 29,000 acres and 14% city water coverage create elevated humidity that amplifies mold compared to drier DFW suburbs. Alternaria peaks summer-fall. Cladosporium is the most common outdoor mold year-round. Aspergillus and Penicillium are prevalent indoors. The Elm Fork riparian zone, LLELA wetlands, and lake shoreline produce continuous mold spores. Storm-driven flooding in Zone AE areas triggers rapid mold surges.
I-35E diesel particulates and PM2.5. DFW Airport flight path ultrafine particulates over southern Lewisville. Barnett Shale legacy gas infrastructure. These function as allergen amplifiers, not primary allergens.
Dust mites thrive in Lewisville's humid subtropical climate and are amplified by lake-effect moisture. Pet dander is significant. Cockroach allergens are common in older housing stock near Old Town. Indoor mold risk is elevated in lake-adjacent and flood-zone properties.
Severity: Moderate to High. Mountain cedar (Ashe juniper) pollen drifts north from the Hill Country and Cross Timbers, reaching clinically significant levels in the DFW area. Cedar fever symptoms peak December-February. Cedar elm and juniper add local pollen. Lewisville Lake humidity maintains elevated mold. Dust mites peak indoors with closed-window heating season.
Severity: Moderate to High. Oak begins active pollination across Cross Timbers woodland. Cedar elm and American elm produce early pollen. Ash and mulberry start. Rain-triggered Blackland Prairie grass greening begins on LLELA and surrounding prairies. Morning fog from Lewisville Lake concentrates allergens at breathing height.
Severity: Severe. Lewisville's worst allergy period. Oak peaks across Cross Timbers woodland. Pecan peaks April-May. Hackberry, cottonwood, sycamore, mulberry, and Bradford pear overlap. Grass pollen rises with Bermuda and native prairie species. Spring thunderstorms trigger rapid mold growth. LLELA restored prairie produces heavy native grass and wildflower pollen. Multiple allergen types airborne simultaneously.
Severity: High. Bermuda grass dominates. Johnson grass peaks along roadsides. Native prairie grasses continue. Mesquite peaks May-June. Summer heat (mid-90s to 100°F+) combines with Lewisville Lake humidity for elevated dust mite and mold conditions. Alternaria mold increases. Lake breezes redistribute allergens into residential areas.
Severity: Severe. Ragweed reaches peak levels — North Texas has some of the highest ragweed concentrations in the US. Pigweed, lamb's quarters, dock, and marsh elder add weed pollen. Alternaria peaks. Fall tropical moisture remnants can trigger flooding and rapid mold growth in Zone AE areas. Late-season grass pollen continues.
Severity: High. Late ragweed tapers. Cedar elm produces fall pollen. First Mountain cedar drift may begin in late November. Fall rains trigger mold surges. Leaf decomposition on lake shoreline and in riparian zones produces Cladosporium and Aspergillus spores.
Lewisville sits in the eastern Cross Timbers — a distinctive ecological transition zone between the Texas Blackland Prairies to the east and the Grand Prairie to the west. This means you're exposed to allergens from two different biomes simultaneously: Blackland Prairie grasses and forbs from the east, and post oak savannah and cedar from the Cross Timbers woodland to the west. Few DFW cities straddle this ecological boundary as distinctly as Lewisville. If allergy medications work for some seasons but fail in others, this dual-biome exposure may explain why — you may be sensitized to allergens from one biome but not the other.
Lewisville Lake covers 29,000+ acres with 183 miles of shoreline, and water constitutes 14% of the city's total area. The Elm Fork of the Trinity River, Prairie Creek, and Timber Creek add further moisture. This lake-effect humidity meaningfully elevates mold exposure compared to drier DFW suburbs. Residents near the lake shoreline, the Elm Fork riparian zone in southeast Lewisville, and the LLELA nature preserve experience the highest moisture-driven mold and riparian pollen exposure. Run dehumidifiers in lakeside and creekside homes, especially during humid summer months.
While Lewisville doesn't have native Ashe juniper (Mountain cedar) populations, it sits in the path of cedar pollen drift from the Hill Country and Cross Timbers. December through February, cedar pollen travels north on prevailing winds and can reach DFW-area cities at clinically significant levels. "Cedar fever" symptoms — severe sneezing, watery eyes, congestion, fatigue — affect many North Texas residents. If you experience these symptoms in winter when other pollen is low, cedar drift is the likely trigger.
Interstate 35E runs directly through Lewisville, carrying heavy truck and commuter traffic between Dallas, Denton, and points north. This produces significant diesel particulate and PM2.5 exposure along the corridor. Neighborhoods near I-35E — particularly along the central spine from Old Town to Vista Ridge — experience the highest traffic-related air pollution. These pollutants amplify biological allergen responses. Time outdoor exercise for early morning before rush hour or late evening, and use HEPA + activated carbon air purifiers in homes near the highway.
Lewisville Lake generates localized breeze patterns: afternoon onshore breezes carry lake moisture and shoreline vegetation pollen into adjacent neighborhoods, while morning calm allows pollen and mold to settle. The LLELA nature preserve (2,600 acres of restored prairie and woodland) generates substantial native grass, wildflower, and oak pollen that drifts into residential areas on lake breezes. If your symptoms consistently worsen in the afternoon, lake-breeze-delivered allergens may be the driver.
The river delta at the southern end of Lewisville Lake and the Elm Fork riparian zone in southeast Lewisville are designated FEMA Zone AE flood areas. After heavy rainfall events — particularly spring thunderstorms and fall tropical moisture — standing water in flood-prone areas creates rapid mold growth. Residents in flood-adjacent neighborhoods should check crawl spaces, basements, and garages for moisture after storms and run dehumidifiers for 48-72 hours after flooding events.
March through May are worst for tree pollen, with oak, elm, pecan, and ash producing overlapping waves. Grass pollen runs April through October. August through November brings severe ragweed — North Texas is one of the highest ragweed regions in the US. December through February adds Mountain cedar pollen drift from the Hill Country. Mold is elevated year-round due to Lewisville Lake humidity.
Lewisville Lake covers 29,000+ acres and water constitutes 14% of the city's area. This creates localized lake-effect humidity that elevates mold exposure compared to drier DFW suburbs. The 2,600-acre LLELA nature preserve generates restored native prairie and woodland allergens. Afternoon lake breezes carry shoreline vegetation pollen and mold spores into adjacent neighborhoods.
Lewisville sits in the eastern Cross Timbers — a transitional ecological zone between the Texas Blackland Prairies and the Grand Prairie. This means exposure to allergens from two distinct vegetation communities simultaneously: Blackland Prairie native grasses and Cross Timbers post oak woodland. This dual-biome positioning creates overlapping allergen seasons uncommon in cities within a single biome.
Cedar fever is caused by Mountain cedar (Ashe juniper) pollen, which drifts north from the Hill Country and Cross Timbers to reach DFW-area cities at clinically significant levels from December through February. Symptoms include severe sneezing, watery eyes, congestion, and fatigue. Many Lewisville residents experience cedar fever despite no native Mountain cedar growing nearby.
Yes. HeyAllergy provides telemedicine appointments with board-certified allergists licensed in Texas. No waitlist. Available throughout the DFW metroplex including Lewisville, Flower Mound, Highland Village, The Colony, Carrollton, Coppell, Denton, and surrounding communities.
HeyPak® sublingual immunotherapy drops are customized based on allergy blood test results. For Lewisville residents, this targets local oak, elm, pecan, Mountain cedar, Bermuda grass, ragweed, mold, and dust mite allergens specific to the North Texas Cross Timbers region. Daily drops retrain your immune system with improvement in 3–6 months. Starting at $47/month.
HeyAllergy accepts Medicare and most major PPO health plans, including United Healthcare, Anthem Blue Cross Blue Shield, Cigna, Aetna, Humana, Oscar, and Tricare. Tax ID: 85-0834175.
Lewisville is a city of 111,822 (2020 census) in southern Denton County, approximately 20 miles northwest of downtown Dallas within the Dallas-Fort Worth metroplex. Originally called Holford's Prairie, the settlement dates to the early 1840s and incorporated in 1925. Lewisville sits at a distinctive ecological boundary: the eastern Cross Timbers, a transitional zone between the Texas Blackland Prairies to the east and the Grand Prairie to the west. This dual-biome positioning creates an allergen environment fundamentally different from cities situated entirely within either prairie type. The city covers 42.5 square miles at approximately 550 feet elevation, with 14% of its area covered by water — including Lewisville Lake, the Elm Fork of the Trinity River, and two tributary creeks.
Lewisville Lake is the defining geographic feature of the city. The 29,000+ acre reservoir with 183 miles of shoreline was created when the U.S. Army Corps of Engineers completed the Garza-Little Elm Dam in 1955, impounding the Elm Fork of the Trinity River. The lake serves as a primary water supply for Dallas and surrounding communities and is a major recreational hub. For allergy purposes, this massive water body creates localized lake-effect humidity that elevates mold exposure compared to drier DFW suburbs. The 2,600-acre Lewisville Lake Environmental Learning Area (LLELA) preserves restored prairie, woodland, and wetland habitats that generate substantial native allergen loads. The Elm Fork riparian zone in southeast Lewisville and the river delta at the lake's southern end are designated FEMA flood zones.
The Cross Timbers is an ancient ecological region — a belt of post oak and blackjack oak woodland interspersed with prairie that once stretched from Texas to Kansas. Lewisville's position in the eastern Cross Timbers means native post oak, blackjack oak, cedar elm, hackberry, and bois d'arc are significant pollen producers. The Blackland Prairie influence brings native bluestem grasses, switchgrass, Indian grass, and diverse forbs. This ecological duality creates overlapping allergen seasons from two distinct vegetation communities. LLELA's prairie restoration efforts have reintroduced many native species, creating a substantial allergen reservoir adjacent to residential areas.
Lewisville's population has grown from 24,273 (1980) to over 111,000, driven by DFW Airport's opening in 1974 and I-35E corridor development. The 2021 annexation of Castle Hills added approximately 3,000 acres and 18,000 residents. I-35E runs through the city's center, carrying heavy Dallas-to-Denton traffic. The DCTA A-train commuter rail connects Lewisville to Denton (north) and Dallas's DART Green Line (south) via three local stations. Vista Ridge Mall and major retail development cluster at the I-35E and Round Grove Road interchange. This transportation infrastructure generates diesel particulate and PM2.5 exposure that amplifies biological allergen responses.
Lewisville has a humid subtropical climate with hot summers, mild winters, and no dry season. Average summer highs reach the mid-to-upper 90s°F, with frequent 100°F+ days. Spring (March-May) brings severe thunderstorm season with potential tornadoes, hail, and heavy rainfall that triggers rapid mold growth. Fall can bring tropical moisture remnants from the Gulf of Mexico. Lewisville Lake's massive water surface amplifies local humidity, particularly during summer, creating conditions favorable for mold and dust mite proliferation that drier DFW suburbs don't experience at the same intensity.
Lewisville sits above the Barnett Shale, a geological formation containing significant natural gas reserves. While natural gas extraction has declined in urban Denton County, legacy well sites and associated infrastructure remain. Combined with I-35E traffic, DFW Airport proximity (flight paths cross over southern Lewisville), and industrial development along the highway corridor, this creates a complex air quality profile that layers onto biological allergen exposure.
Lewisville's Cross Timbers dual-biome positioning between Blackland Prairies and Grand Prairie vegetation communities, 29,000-acre Lewisville Lake creating lake-effect humidity and elevated mold exposure, LLELA nature preserve generating restored native prairie allergens, I-35E corridor traffic pollution, humid subtropical storm-driven mold surges, and Mountain cedar pollen drift from the Hill Country create an allergy environment unique among DFW-area suburbs. HeyAllergy connects Lewisville residents with board-certified allergists through telemedicine. Patients receive allergy blood testing, personalized treatment, and HeyPak® sublingual immunotherapy drops custom-formulated for North Texas allergens. Treatment starts at $47/month. No needles, no clinic visits, no waitlist.
