Frequently Asked Questions
About Pollen Allergies
Why are my allergies worse some days than others?
Several factors affect day-to-day symptom severity:
- Pollen counts vary daily depending on weather, temperature, and wind
- Time of day matters — pollen often peaks mid-morning to afternoon
- Rain temporarily reduces pollen, but thunderstorms can make symptoms worse
- The priming effect — repeated exposure makes your immune system more reactive over time
- Cross-reactive foods can worsen symptoms during pollen season
See our Understanding Pollen Counts guide for more details.
Can allergies develop later in life?
Yes. While many people develop allergies in childhood, adults commonly develop new allergies too, especially:
- After moving to a new area with different plants
- Following changes to the immune system (illness, pregnancy, aging)
- With new or increased exposure to allergens
If you suspect new allergies, see an allergist for testing.
Are pollen allergies hereditary?
Genetics play a role. If one parent has allergies, children have about a 30-50% chance of developing them. If both parents do, the risk increases to 60-80%.
However, genetics determine the tendency to develop allergies, not which specific allergens will affect you. Environment and exposure matter too.
What’s the difference between allergies and a cold?
| Symptom | Allergies | Cold |
|---|---|---|
| Duration | Weeks to months (during pollen season) | 7-10 days |
| Onset | Sudden when exposed | Gradual over 1-3 days |
| Nasal discharge | Clear and watery | May become thick and yellow/green |
| Fever | Never | Sometimes |
| Itchy eyes/nose | Very common | Rare |
| Sneezing | Frequent, in bursts | Occasional |
| Time of year | Seasonal pattern | Any time, peaks in winter |
Managing Symptoms
Do air purifiers help with pollen allergies?
Yes, HEPA air purifiers can significantly reduce indoor pollen. For best results:
- Choose purifiers rated for your room size
- Look for True HEPA filters (99.97% capture at 0.3 microns)
- Run continuously during pollen season, especially in bedrooms
- Replace filters according to manufacturer guidelines
Air purifiers work best alongside other strategies like keeping windows closed and changing out of outdoor clothes.
When should I take allergy medication?
For best results:
- Start early: Begin antihistamines 1-2 weeks before your typical season
- Be consistent: Daily use beats occasional use
- Morning dosing: Take before going outside if possible
- Nasal sprays: Work best with consistent daily use; effects build over days
Talk to your doctor or pharmacist for personalized advice, especially if over-the-counter meds aren’t enough.
Should I see an allergist?
Consider it if:
- Over-the-counter medications don’t provide enough relief
- You have asthma symptoms alongside allergies (wheezing, chest tightness)
- Symptoms significantly impact work, sleep, or quality of life
- You want to identify exactly what you’re allergic to
- You’re interested in immunotherapy (shots or sublingual tablets)
- Symptoms are severe or getting worse each year
Food and Cross-Reactivity
Why does eating certain foods make my mouth itch during pollen season?
This is Oral Allergy Syndrome (OAS), also called pollen-food syndrome. Proteins in certain raw fruits, vegetables, and nuts resemble pollen proteins, so your immune system reacts to them too.
Common combinations:
- Birch pollen → apples, pears, cherries, carrots, hazelnuts
- Grass pollen → melons, tomatoes, oranges
- Ragweed → bananas, melons, cucumbers
Learn more in our Cross-Reactivity Guide.
Can I still eat foods that cause oral allergy symptoms?
Usually yes, with some adjustments:
- Cooking usually helps: Heat breaks down the problematic proteins
- Peeling may help: Trigger proteins often concentrate in the skin
- Symptoms vary seasonally: You may tolerate foods outside pollen season
However, stop eating any food that causes symptoms beyond mild mouth tingling, and see a doctor if reactions seem to worsen.
About Pollen.city
How often is the data updated?
Pollen forecasts are updated daily, typically around 6 AM local time for each city. Weather and air quality data update more frequently throughout the day.
How accurate are pollen forecasts?
Our forecasts use data from Google’s Pollen API, combining weather models, historical pollen data, and plant phenology. Like weather forecasts, accuracy is highest for the current day and decreases further out.
Actual symptoms may vary due to:
- Local vegetation differences
- Individual sensitivity
- Microclimate effects
- Measurement limitations
What pollen types do you track?
Three main categories:
- Tree pollen: Birch, oak, maple, alder, hazel, pine, and more
- Grass pollen: Various species that cause hay fever
- Weed pollen: Ragweed, mugwort, and others
We show individual species when available, along with whether they’re currently in season.
Can I get notifications about pollen levels?
Yes! On any city page, subscribe to push notifications. We’ll send daily alerts about pollen and air quality levels during pollen season.