Spring Allergies: Causes, Symptoms and Relief
When the trees bloom, so does the sneezing. Here's what drives spring allergies, when they peak, and how to get ahead of them.
Quick answer: spring allergies in brief
Short answer: spring allergies are mostly tree pollen — oak, birch, cedar, maple — with early-spring mold adding to it. The season typically runs February into early summer and peaks March to May. Cut your exposure, start daily medicine before the season rather than after symptoms arrive, and use a steroid nasal spray if congestion is the main problem.
Spring allergies are mainly caused by tree pollen — oak, birch, cedar, maple and others — with mold spores adding to early-spring symptoms. When you breathe the pollen in, your immune system releases histamine, causing sneezing, a runny or blocked nose and itchy, watery eyes. The season typically runs February into early summer, peaking in March–May, and is starting earlier as the climate warms. You can't avoid pollen entirely, but checking the forecast, reducing exposure and starting the right medicine a couple of weeks before your season makes a big difference. It's a form of seasonal allergies, also called hay fever.
What causes spring allergies?
Tree pollen is the main culprit behind spring allergies. As the weather warms, trees release huge amounts of tiny, light, dry pollen designed to travel on the wind — which means it easily reaches your eyes, nose and lungs. Common offenders include oak, birch, cedar, maple, elm and ash.
There's a second, often-overlooked trigger: mold spores. As snow melts and the ground warms in early spring, mold that grew over winter releases spores that can set off symptoms too. In all cases, the problem isn't the pollen or spores themselves — it's that your immune system misreads them as a threat and releases histamine, driving the familiar reaction. The medical name is seasonal allergic rhinitis; the trigger is pollen.
When does spring allergy season start and peak?
In much of the U.S., spring allergy season runs from February into early summer, peaking through March, April and May. Tree pollen is the first pollen of the year, so it kicks the season off — and in warmer southern regions, trees can begin releasing pollen in late winter.
| Time | What's happening |
|---|---|
| Late winter – February | Earliest trees begin (earlier in warm regions) |
| March – May | Tree pollen peaks; symptoms at their worst |
| Late spring – early summer | Tree pollen fades as grass pollen takes over |
Exact timing depends on where you live and the weather. See the full year in our allergy season calendar, and what follows in fall allergies.
Why spring allergies start earlier each year
If your allergies seem to arrive sooner and hang around longer than they used to, you're right. Research shows pollen seasons across North America are beginning earlier and lasting longer, with higher pollen counts, largely driven by a warming climate.
Milder winters mean fewer hard freezes to hold plants back, so trees start pollinating sooner — sometimes in late winter rather than early spring. This shift is also linked to more people being diagnosed with seasonal allergies for the first time, including in adulthood. The practical takeaway: don't wait for symptoms to tell you the season has started — get your plan ready early.
How much earlier, exactly
The shift has been measured, and the usual way it is quoted gets it slightly wrong. A 2021 study in PNAS analysed 60 North American pollen monitoring stations across 821 site-years from 1990 to 2018:
| What changed | How much, 1990–2018 | Share attributed to human-caused climate change |
|---|---|---|
| Season start date | About 20 days earlier | Roughly 35–66% |
| Season length | About 8 days longer | Roughly 19–35% |
| Pollen concentration | Up about 21% | Roughly 4–8% |
You will often see this reported as "pollen seasons are 20 days longer." They are not. Seasons begin about 20 days earlier and run about 8 days longer — which is precisely why spring is the season where the change is felt most. Symptoms now start in weeks that used to be winter.
Read the attribution honestly too: climate change accounts for a large share of the shift in timing but only a small share of the rise in pollen concentration. Either way the practical consequence is the same, and it is a scheduling problem more than a medical one — if you still start your medicine in the same week you did ten years ago, you may now be starting late. More in why pollen seasons are getting longer and why are my allergies so bad this year?
Spring allergy symptoms
Symptoms show up when your trigger pollen is in the air and ease once exposure drops. The most common are:
- Sneezing, often in bursts
- Runny nose with clear mucus
- Nasal congestion and a blocked nose
- Itchy nose, throat and eyes
- Watery, red eyes
- Postnasal drip and a cough
- Tiredness and disturbed sleep
- Headache or sinus pressure
Spring allergies can also flare asthma and irritate sensitive skin (eczema). If pollen brings on wheezing or breathlessness, treat that as more than a nuisance — see the safety note below. For the full picture, see our allergy symptoms guide.
Spring allergies or a cold?
Early spring is peak season for both pollen and lingering winter colds, so it's easy to mix them up. The quickest tells: allergies itch (eyes, nose, throat), never cause a fever, and last for weeks while pollen is around; a cold builds over a day or two, may bring a mild fever or body aches, and clears in about a week to ten days. You can even have both at once. Full breakdown in allergies vs. a cold.
Why some foods make spring allergies feel worse
If your mouth or throat itches when you eat certain raw fruits and vegetables during pollen season, you may have oral allergy syndrome (pollen-food syndrome). It happens because the proteins in some foods look, to your immune system, a lot like tree-pollen proteins.
Birch and other tree pollens commonly cross-react with raw apple, cherry, peach, plum, carrot and hazelnut, causing a tingly, itchy mouth, lips or throat — usually mild and short-lived. Cooking the food often removes the reaction. It's typically harmless, but because swelling or throat symptoms can occasionally be more serious, mention it to a doctor, and treat any trouble breathing as an emergency (see below).
The cross-reaction lists are specific enough to be useful. The American College of Allergy, Asthma & Immunology sets them out by pollen:
| If you react to | Raw foods that commonly cross-react |
|---|---|
| Birch pollen (the classic spring one) | Apple, almond, carrot, celery, cherry, hazelnut, kiwi, peach, pear, plum |
| Grass pollen (as spring turns to summer) | Celery, melon, orange, peach, tomato |
| Ragweed pollen (later in the year) | Banana, cucumber, melon, sunflower seeds, zucchini |
ACAAI explains the mechanism plainly: the immune system recognises the pollen and similar proteins in the food, and directs an allergic response at the food. Symptoms usually stay local and subside quickly once the food is swallowed or removed from the mouth, and cooked versions are normally fine because heating distorts the protein enough that the immune system no longer recognises it. A raw apple bothers you; apple pie does not.
When it is more than an itchy mouth
ACAAI notes that although it is uncommon, symptoms can progress beyond the mouth, with anaphylaxis reported in about 1.7% of people affected. Hives elsewhere, vomiting, trouble breathing or faintness are no longer a mild local reaction. Speak to an allergist about whether you should carry an epinephrine auto-injector. More in oral allergy syndrome.
How to treat spring allergies
The best results come from pairing exposure control with the right medicine — and timing it well. This is general information, not dosing advice; a pharmacist can help you choose.
- Antihistamines — non-drowsy options ease sneezing, itching and a runny nose. See antihistamines.
- Steroid nasal sprays — the most effective option for congestion and sinus pressure, used daily. See nasal sprays.
- Saline nasal rinses — flush pollen from the nose (use distilled, sterile or previously boiled water). See natural remedies.
- Antihistamine eye drops — for itchy, watery eyes. See itchy eyes.
- Immunotherapy — allergy shots or under-the-tongue tablets can reduce your reaction to tree pollen long-term.
Start a couple of weeks early. Allergists recommend beginning daily medicine — especially steroid nasal sprays, which take days to build up — about two to four weeks before your season usually starts. It's easier to prevent inflammation than to calm it once symptoms are severe. See the full plan in our treatment & relief guide.
Getting the timing right
Two details decide whether your spring plan works: when you start, and how much you trust the daily number.
How far ahead to start
Guidance varies a little by source and by medicine. The Allergy & Asthma Network advises that most people should start allergy medicine about one to two weeks before their pollen season begins. Steroid nasal sprays are the reason to lean toward the earlier end, since they need several days of daily use to reach full effect, and some allergists suggest a little more lead time for them. Starting earlier than needed does no harm; starting late means spending your worst week waiting for the medicine to catch up.
The practical version: put a reminder in the calendar for a fortnight before the month your symptoms usually begin, and note that in a warming climate that month may now be earlier than the one you remember.
The pollen count is a lagging indicator
Counts are useful but not live. The Allergy & Asthma Network points out that daily counts often represent collections made 24 to 48 hours earlier. So a low reading today does not promise a low-pollen afternoon. Use it as a trend and let the weather fill in the rest: warm, dry and windy pushes counts up, steady rain washes the air clean, and early morning through early afternoon is usually the worst window for outdoor exertion.
Our pollen count guide explains what the numbers mean, tree pollen allergy covers the specific spring triggers, and allergy season by region shows how far the timing shifts across the country.
How to reduce your pollen exposure
Cutting your exposure is the foundation of relief — and it makes any medicine work better.
- Check the daily pollen forecast; plan around high-count days and the early morning, when pollen peaks.
- Keep windows and doors closed at home and in the car; use air conditioning rather than window fans.
- Run a HEPA air purifier and vacuum with a HEPA-filter cleaner.
- Shower and change clothes after being outdoors so you don't carry pollen to bed.
- Dry laundry indoors during your season — outdoor drying collects pollen.
- Wear wraparound sunglasses, and a mask for mowing, raking or gardening.
- Wash bedding regularly in hot water, and wipe down pets after they've been outside.
Spring allergies in children
Spring allergies are common in children — about one in five kids has seasonal allergies — and they're easy to miss because the signs can look like a run of colds. Watch for frequent nose-rubbing, dark under-eye circles, mouth-breathing, itchy eyes, and a clear runny nose without a fever that shows up each spring.
Because untreated symptoms can disrupt sleep, concentration and school, and because suitable products differ by age, it's best to check with a pediatrician rather than use adult medicines by guesswork. More in allergies in children.
Go deeper on your spring triggers
| If this is you | Guide |
|---|---|
| Oak, birch, cedar or maple is your trigger | Tree pollen allergy |
| Symptoms carry on into summer | Grass pollen and summer allergies |
| Eyes are the worst part | Eye allergies and allergy eye drops |
| A cough that will not settle | Allergy cough |
| Pollen affects your chest | Allergic asthma |
| Smoke or poor air quality days | Air quality and allergies |
| Choosing between medicines | Allergy medicine |
| Rinsing and filtering | Saline rinsing, HEPA filters and air purifiers |
| You want to treat the cause, not the season | Allergy shots and under-the-tongue tablets |
When to see a doctor
See a doctor if over-the-counter medicine isn't controlling your symptoms, if they disrupt your sleep or daily life, or if you're not sure what you're reacting to. A simple allergy test can confirm exactly which spring pollens affect you, and an allergist can tailor a stronger plan, including immunotherapy. More on timing in when to see a doctor for allergies.
Breathing symptoms need a doctor, not home remedies
If spring pollen brings on wheezing, chest tightness or shortness of breath, see a healthcare provider — this can be allergic asthma. And although inhaled pollen rarely causes a severe whole-body reaction, call 911 for any trouble breathing or swelling of the face, lips, tongue or throat. See our allergy safety guide.
Spring allergies: frequently asked questions
When do spring allergies start?
What causes spring allergies?
How do I stop spring allergies?
Why are my spring allergies worse this year?
How much earlier are spring pollen seasons actually starting?
How far in advance should I start spring allergy medicine?
Why does my mouth itch when I eat raw apple in spring?
How accurate is the daily pollen count?
How common are seasonal allergies in children?
How we create and review this guide
This guide is written for a general audience using patient-education material from the authoritative sources below, not blogs or forums:
- American Academy of Allergy, Asthma & Immunology (AAAAI) & National Allergy Bureau
- American College of Allergy, Asthma & Immunology (ACAAI)
- Asthma and Allergy Foundation of America (AAFA)
- Mayo Clinic
- U.S. Centers for Disease Control and Prevention (CDC)
Sources for the specific figures on this page
- Anderegg WRL, Abatzoglou JT, Anderegg LDL, Bielory L, Kinney PL, Ziska L. Anthropogenic climate change is worsening North American pollen seasons (opens in a new tab). PNAS 2021. Sixty North American pollen stations across 821 site-years, 1990–2018: seasons starting about 20 days earlier, lengthening about 8 days, and concentrations rising about 21%, with human forcing attributed roughly 35–66% of start-date trends, 19–35% of season-length trends and 4–8% of annual concentration trends.
- Allergy & Asthma Network. Pollen allergy (opens in a new tab). Starting allergy medication about one to two weeks before pollen season begins; daily pollen counts often representing collections made 24 to 48 hours earlier; tree, grass and weed season timing; and exposure-reduction measures.
- American College of Allergy, Asthma & Immunology. Pollen food allergy syndrome (opens in a new tab). Cross-reacting proteins in pollen and raw foods; the birch, grass and ragweed cross-reaction lists; symptoms staying local and subsiding quickly once the food is swallowed or removed; cooked foods normally tolerated because heating distorts the protein; and anaphylaxis reported in about 1.7% of affected people.
- American College of Allergy, Asthma & Immunology. Allergy facts and figures (opens in a new tab). National Health Interview Survey data for 2021, including hay fever reported in 18.9% of US children.
- American College of Allergy, Asthma & Immunology. Hay fever (allergic rhinitis) (opens in a new tab). Intranasal corticosteroids described as the single most effective drug class for allergic rhinitis, and rebound swelling from prolonged decongestant nasal spray use.
Medical disclaimer: This guide is for general education and isn't a substitute for personalized medical advice. It doesn't provide dosing. Always talk to a qualified healthcare professional about your symptoms and treatment.
MDMedically reviewed
Dr. Hannah H. Walford, MD
Allergist and Immunologist
- Website role
- Owner, Medical Director and Medical Reviewer of Allergy Relief Guide
- Professional affiliation
- Stanford Health Care / Menlo Medical Clinic, Menlo Park, California
- Areas of expertise
- Food allergy, eczema, allergic rhinitis, sinusitis and asthma
Dr. Hannah H. Walford is a board-certified allergist and immunologist experienced in caring for adults and children with allergic conditions. Her areas of expertise include food allergy, eczema, allergic rhinitis, sinusitis and asthma. She provides medical leadership and review oversight for the educational health content published by Allergy Relief Guide.
Medical content is provided for education and is not a substitute for diagnosis or individualized medical care.
Related guides
Seasonal allergies
The full year, season by season.
Pollen allergy
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Allergy season calendar
When each pollen peaks through the year.
Treatment & relief
Every option, step by step.
Tree pollen allergy
The specific spring trigger, tree by tree.
Pollen counts
What the daily number actually means.
Allergy medicine
Which type suits which symptom.
Oral allergy syndrome
Itchy mouth from raw fruit in pollen season.
Get ahead of tree-pollen season
See exactly when spring pollen peaks so you can start relief before symptoms hit.
View the allergy season calendar