Frequently Asked Questions
About Pollen Allergies
Why are my allergies worse some days than others?
Several factors affect daily symptom severity:
- Pollen counts vary daily based on weather, temperature, and wind
- Time of day matters - pollen levels often peak mid-morning to afternoon
- Rain temporarily reduces pollen but thunderstorms can worsen symptoms
- The priming effect - repeated exposure makes your immune system more reactive over time
- Cross-reactive foods may worsen symptoms during pollen season
Check our Understanding Pollen Counts guide for more details.
Can allergies develop later in life?
Yes, allergies can develop at any age. While many people develop allergies in childhood, it’s common for adults to develop new allergies, especially:
- After moving to a new geographic area with different plants
- Following changes in the immune system (illness, pregnancy, aging)
- With increased or new exposures to allergens
If you suspect new allergies, consult an allergist for proper testing.
Are pollen allergies hereditary?
Genetics play a role in allergies. If one parent has allergies, their children have about a 30-50% chance of developing allergies. If both parents have allergies, the risk increases to 60-80%.
However, genetics determine the tendency to develop allergies, not which specific allergens will affect you. Environmental factors and exposure patterns also play important roles.
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 to allergen | 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 levels. For best results:
- Choose purifiers rated for your room size
- Look for True HEPA filters (capture 99.97% of particles 0.3 microns or larger)
- Run continuously during pollen season, especially in bedrooms
- Replace filters according to manufacturer guidelines
Air purifiers work best as part of a comprehensive strategy that includes keeping windows closed and removing outdoor clothing.
When should I take allergy medication?
For best results:
- Start early: Begin taking antihistamines 1-2 weeks before your typical season starts
- Be consistent: Daily use is more effective than occasional use
- Morning dosing: Take medication before going outside if possible
- Nasal corticosteroids: Work best with consistent daily use; effects build over several days
Consult your doctor or pharmacist for personalized advice, especially if over-the-counter medications aren’t providing adequate relief.
Should I see an allergist?
Consider consulting an allergist if:
- Over-the-counter medications don’t provide adequate relief
- You experience asthma symptoms alongside allergies (wheezing, chest tightness)
- Symptoms significantly impact your quality of life, work, or sleep
- You want to identify exactly what you’re allergic to
- You’re interested in immunotherapy (allergy shots or sublingual tablets)
- Your 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 called Oral Allergy Syndrome (OAS) or pollen-food syndrome. Proteins in certain raw fruits, vegetables, and nuts are similar to pollen proteins. Your immune system mistakes them for pollen and triggers a mild allergic reaction.
Common combinations include:
- 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 precautions:
- Cooking usually helps: Heat breaks down the proteins that cause reactions
- Peeling may help: Trigger proteins are often concentrated in the skin
- Symptoms vary seasonally: You may tolerate foods outside of pollen season
However, stop eating any food that causes symptoms beyond mild mouth tingling and consult a doctor if reactions seem to worsen.
About Pollen.city
How often is the data updated?
Pollen forecasts on Pollen.city are updated daily, typically in the early morning (around 6 AM local time for each city). Weather and air quality data are updated more frequently throughout the day.
How accurate are pollen forecasts?
Our forecasts use data from Google’s Pollen API, which combines multiple data sources including weather models, historical pollen data, and plant phenology. Like weather forecasts, accuracy is highest for the current day and decreases for days further out.
Actual symptoms may vary from forecasts due to:
- Local variations in vegetation
- Individual sensitivity differences
- Microclimate effects
- Measurement limitations
What pollen types do you track?
We track three main categories:
- Tree pollen: Including birch, oak, maple, alder, hazel, pine, and more
- Grass pollen: Various grass species that cause hay fever
- Weed pollen: Including ragweed, mugwort, and other weeds
Within each category, 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, you can subscribe to push notifications. We’ll send you daily alerts about pollen and air quality levels in your chosen city during pollen season.