Allergy Season In The United States: A Complete Guide

Written by Ashley Haugen
Updated: May 12, 2023
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When the sneezin’ season hits, allergy sufferers everywhere groan — and rub their eyes and wipe their noses and generally feel kind of crummy for a while as they wait for their anti-histimines to kick in. Generally speaking, allergy season in the United States is from February through early summer when the trees and plants have finally fully bloomed. But lest we forget fall allergy season, when ragweed wreaks havoc on sinuses everywhere — typically from late summer to November.

Here, we will discuss allergy season in the United States, including what plants and trees are in bloom — and when — as well as offer you a suggestion or two in the way of allergy relief. Let’s get to it!

bradford pears along a path

When the winter gives way to spring, stock up on your tissue. It’s the beginning of spring allergy season!

© Birnbaum

Allergy Season in the Southeast

STATES: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, West Virginia

Allergy season in the Southeast can be brutal. In fact, many argue that there are no true allergy seasons in the South because the weather — particularly in the Southern-most part of the region — stays warm for longer. That means plants may never fully go dormant for the winter, which allows common allergens like pollen to run rampant for much of the year. The chronic exposure to allergens causes things like stuffy, runny noses, sore throat, sinus headache and plenty of sneezing.

In the spring, the culprit is largely tree pollen. The leaves are returning and grasses are waking up from the winter. In particular, trees like oak, pine, willow, and birch are the main offenders. The season kicks off in February in some states and doesn’t slow down till summer. Fall typically lasts from August to November, with ragweed being primarily to blame. Let’s dig deeper into allergy season in the Southeast.


The allergy season in Alabama can be difficult to anticipate. Given the mild winters found in many parts of Alabama, most plants don’t die off, which extends their growing season and your misery. The average Alabamian has allergies from February or March until October, if not November, given the long-growing potential of ragweed. Other common plants that cause allergies include beech trees, juniper trees, thistles, ryegrass, and mildew during the wintertime. Read more about Alabama’s allergy season here.


Allergies are pretty much part of life in the South. In Arkansas, common culprits for spring allergies, which typically last from late February through early May, are ash, cedar, hickory, mulberry, oak, privet, walnut, and willow trees. In early June, welcome summer allergy season with grass allergies caused by types such as rye, Bermuda, fescue, orchard, and bent grasses. Rounding out Arkansas’ allergy season is fall, which starts in mid-August and peaks in September with all the weeds — pigweed, ragweed and Amaranth to be specific. Find out more about Arkansas’ allergy season here.


Just like we’ve previously mentioned, the allergy season in Mississippi is a year-round affair. Depending on how the weather is in any given year, the average Mississippi resident may suffer from February until November, and some plants may even still be in bloom during the wintertime! Trees are the worst in the springtime, while grasses and weeds keep Mississippians sneezing the rest of the year. Read all about Mississippi’s allergy season here.

North Carolina

North Carolina experiences a not-unbearable allergy season generally running from late March to November with peak months being April through June. Allergens include tree and grass pollens as well as various weeds. Learn more about North Carolina’s allergy season here.

West Virginia

West Virginians typically experience the worst of allergy season in the springtime, when birch, ash, cedar, hickory, walnut, privet, oak, and willow trees are in bloom. Look for the sneezing to commence sometime in early March and last through May. Grasses are problematic in summer with a wide variety causing problems. Finally, fall brings ragweed allergies along with amaranth, orache, and wormwood. Find out more about West Virginia’s allergy season here.

ragweed plant

Ragweed is a common cause of allergies, particularly in the fall.


Allergy Season in the Midwest

STATES: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin

If you live in the Midwest, your allergy season(s) may be shorter than your southern neighbors’ season. Typically grass and tree pollen — along with mold and dust — start to bother allergy sufferers sometime in late spring, and in the farthest northern areas, perhaps early summer.

Generally speaking, fall allergy season begins in late summer and can last thru October. And again, ragweed is the common culprit. Let’s take a closer look at state-by-state allergy seasons to hone in on specifics.


With diverse climates and dusty plains, Kansas is a terrible state for allergies. While the frigid winters will halt most pollen production, Kansas allergies are at their peak from March until late October. Some of the most common culprits of sneezes and sniffles include ragweed, brome, Kentucky bluegrass, mugwort, hickory trees, sycamore trees, and walnut trees. Learn more about the Kansas allergy season here.


Missouri’s peak allergy season is April through June and September. As is typical in most states, the trees are causing issues in the spring, and weeds are the issue in the fall. Ragweed, grasses, and trees like oak, walnut, ash, and others are to blame for your allergy issues. Find out more about Missouri’s allergy season here.


Wisconsin’s location serves it well when it comes to season allergies, which are shorter in comparison to other states. Spring allergy season typically lasts from mid-March to late May, while fall allergies are worst from August to November. Find out more about Wisconsin’s allergy season here.

Allergy Season in the West

STATES: Alaska, California, Colorado, Hawaii, Idaho, Montana, Nevada, Oregon, Washington, Wyoming

The West is a pretty vast region, so it stands to reason that one allergy season does not fit all states within. And it can differ, even, within a state itself. California, for example, has a variety of allergy seasons. Southern California really only gets a break from seasonal allergies in February. Northern California, on the other hand, gets a longer break — albeit only slightly longer.

Grass, tree, and weed pollens are the usual suspects. But let’s dig deeper into each state in this region’s allergy season.


The dry environment in Nevada means that pollen can travel more easily causing problems for allergy sufferers across various regions. Nevada experiences two peak allergy seasons in the fall and in the spring. Weed allergies from plants such as ragweed and sagebrush are worse during fall and tree allergies such as from mulberry trees cause havoc in the spring. And though Nevada’s heat helps to control allergens in the summer months, the various grasses can cause allergic reactions during this time of the year. Find out more about Nevada’s allergy season here.


Oregon has unusually high pollen counts when compared with other states, and because of that, it’s often ranked as one of the worst states for allergies. Spores, pollens, grasses, and weeds make allergy season last pretty much year-round. Find out more about Oregon’s allergy season here.


Given its fairly dry climate and cold winters, Wyoming doesn’t have as bad of an allergy season as many other states. In fact, the average Wyoming allergy season peaks from March until September, depending on local weather conditions. However, dusty, windy, and dry conditions often leave residents feeling itchy even after all of the trees and plants have stopped blooming! You can read more about Wyoming’s allergy season here.

Allergy Season in the Northeast

STATES: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Washington, DC

As one would expect, the Northeast enjoys a shorter allergy season than many of the other regions of the United States. According to New England Allergy, the major pollen seasons are March and April (tree pollens), and May and June allergies are caused by grass pollens. Finally, fall allergy season in New England in particular is from around mid-August until the first hard frost. Filling in the blanks, look at mold spores to cause allergic reactions — commonly in July and November.

Take a closer look at allergy seasons in each of these Northeastern states.


Given that Delaware is a low-lying state along the Atlantic Ocean, it has a long and potentially grueling allergy season. The pollen count can also be severely affected by winter storms that delay blooming times. Allergies tend to be at their worst during the months of March-June due to a variety of blooming trees, with a brief break in July. However, August-October brings more sneezing with many different grasses and weeds in bloom, including amaranth, cocklebur, and sorrel. Read all about Delaware’s allergy season here.


Maine has a fairly mild spring through fall ensuring allergies can enjoy a decent run during those months. Thanks to its colder winter climate, Maine residents get a break, if only for a few months. Maine’s allergy season typically runs from early March to the first hard freeze. Tree pollens, ragweed, and even dandelion cause issues for allergy sufferers. Find out more about allergy season in Maine here.


Maryland has a pretty temperate climate year-round, but that doesn’t mean it doesn’t have allergy seasons. Look for symptoms to start in early March and last till late November. You may notice the worst of the symptoms in April, June, and September thanks to tree pollens, grasses, and ragweed. Find out more about Maryland’s allergy season here.


In Massachusetts, look for spring allergy season to kick off sometime in late spring as trees begin to bloom. The season tapers off in early summer — just in time for summer allergies to kick in with grasses reviving. Round out the trio with fall allergy season, which typically lasts from August until the first hard frost. While seasonal allergies subside in the winter, be mindful of household allergens like dust and dander. Find out more about Massachusetts’ allergy seasons here.

New Jersey

In New Jersey, look for spring allergy season to kick off as early as mid-February and last till the first freeze. The peak months are April, May, June, and September, with common culprits like trees (oak, hickory, ash, walnut, cedar, privet, willow, and mulberry), weeds (ragweed, lamb’s quarter, wormwood, and orache) and grasses (timothy, bent, corn, sweet vernal, fescue, orchard, and brome) being the cause. Find out more about allergy season in New Jersey here.


According to the Asthma and Allergy Foundation of America, Scranton, PA ranked as 2022’s worst city for allergies. Much of Pennsylvania can likely attest to the unhealthy pollen amounts throughout the year, particularly from February through June and back again in August through October. Some common causes of allergies in this state include willow trees, ragweed, maple trees, pigweed, fescue, and Bermudagrass. Read more about allergies in Pennsylvania here.

Rhode Island

Perhaps surprising — or not — Rhode Island has an infamous reputation for being rough for allergy sufferers, and with such a variety of allergens, it’s somewhat easy to see why. The spring season starts off as early as late February and last thru May with cedar and mulberry trees causing problems. In the summer months, ryegrass and bentgrass are to blame. And in the fall, weed allergies are in full bloom (no pun intended) causing allergic reactions from around mid-August till the first hard frost. Find out more about allergy season in Rhode Island here.


Vermont isn’t well-known for allergies, which makes sense thanks to the fairly cold winters. Spring through fall, however, is just mild enough to cause a bit of an issue for those who struggle with allergies. Oak, maple, birch, hickory, and ash trees, to name just a few, are the spring allergy culprits, while in the summer, it’s grasses that cause problems. In the fall, ragweed, wormwood, amaranth, and orache are the problems. Find out more about Vermont allergy season here.

Allergy Season in the Southwest

STATES: Arizona, New Mexico, Oklahoma, Texas

In the Southwest, look for things like tree and grass pollen as well as Bermuda grass to be problematic on your allergies from late summer to late fall. Peak spring allergy season is typically hovering between March and April.

There are plenty of offenders that bring on sneezing and itchy, watery eyes. Birch, acacia, ash, cedar, and elm trees are just a few. In terms of grass, varieties like meadow fescue, Bahia, rye, and Timothy are to blame. And plenty of weeds will irritate allergy sufferers — cocklebur, sagebrush, Lamb’s Quarters, and ragweed to name a few.

Take a closer look at these Southwest states’ allergy seasons.


While Arizona has a dry climate that suits many people, it maintains a growing season throughout the entire year due to its warmer temperatures. This means that a variety of plants are active in this desert landscape, often leading to plenty of dry eyes and itchy skin! Some common trees, plants, and weeds that cause allergies year-round in Arizona include juniper trees, Russian thistle, ragweed, cottonwood trees, and Bermuda grass. Plus, Arizona is extra dusty, likely leaving you feeling extra sneezy! Read more about Arizona’s allergy season here.

Help for Seasonal Allergy Sufferers

What good is it to discuss the pain points if we don’t offer some potential solutions? We aren’t dispensing medical advice — you should always consult with your personal physician for that, but we can make a few recommendations to ease the symptoms in the immediate term. Things like nasal sprays, eye drops, antihistamine pills can help. And don’t forget the Kleenex. LOTS and LOTS of Kleenex!

  1. Flonase Allergy Relief Nasal Spray
    • Non-drowsy allergy relief nasal spray
    • Provides relief from runny nose, sneezing and itchy eyes
    • Works for indoor and outdoor allergies
    • Easy to use
    • Eligible for HSA and FSA healthcare programs
    Check Amazon
  2. Benadryl Ultratabs Antihistamine Allergy Relief Medicine
    • Trusted name in allergy relief
    • Easy-to-swallow pills
    • Safe and effective allergy relief
    • Doctor-recommended
    Check Amazon
  3. Pataday Once Daily Relief
    • Doctor recommended
    • Antihistamine relief for itchy eyes
    • Fast-acting
    • 24-hour relief
    Check Amazon
  4. Kleenex Facial Tissues with Lotion
    • Trusted name in tissue
    • Soothing lotion is easy on the nose
    • 2-ply construction stands up to sneezes
    Check Amazon

The photo featured at the top of this post is ©

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About the Author

Ashley Haugen is a lifelong animal lover and professional writer and editor. When she's not immersed in, she can be found hanging out with her dogs and birds.

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