The forecast that decides whether today is bearable
Two different numbers get muddled together every spring. Pollen is a count of grains in the air, forecast by type, and it is what matters if the problem is hay fever. Air quality is a measure of particulates and gases, reported on a scale that varies by country, and it is what matters if the problem is asthma, a nearby road or smoke. Apps tend to be good at one and approximate about the other, and picking the wrong one produces a number that looks precise and means very little for you.
What the numbers are actually saying
| What you see | What it measures | What to do with it |
|---|---|---|
| Tree pollen | Birch, alder, hazel and similar, early in the year | The late winter and spring problem |
| Grass pollen | The commonest hay fever trigger, early summer | Check this one specifically, not the total |
| Weed pollen | Nettle, mugwort, ragweed, late summer | Explains symptoms in August that surprise people |
| PM2.5 and PM10 | Fine particles from traffic, burning and dust | The number to watch for asthma and smoke |
| An air quality index | Those readings folded into one figure | Scales differ by country; compare like with like |
| A forecast versus a reading | Modelled ahead versus measured now | A reading from far away is a guess about your street |
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The apps worth having in season
IQAir AirVisual. The most thorough air quality app of the set, with station-level data, a clear explanation of the scale it is using and forecasts a few days ahead.
Plume Labs. Presents pollution as an hourly forecast through the day rather than one number, which is the shape you need to decide when to go for a run.
BreezoMeter. Covers air quality and pollen in one app with a street-level model, so it interpolates rather than showing you the nearest station and calling it your address.
AirCare. Lighter and quicker to read at a glance, with widgets that keep the current figure on the home screen where you will actually see it.
Pollen Count & Alerts. Pollen specifically, broken down by type, with alerts you can set for the one that affects you rather than the overall level.
Pollenflug-Vorhersage. A German pollen forecast with regional detail that general weather apps do not reach. Worth knowing about if you are in or travelling through that region.
AccuWeather. Its allergy and air quality sections are better than most general weather apps, and it is already installed on a great many phones.
The Weather Channel. The same reasoning, with a strong allergy forecast in the regions it covers well and a very good radar for the rain that clears the air.
Windy.com. Shows wind direction and strength as a moving map, which is the honest way to understand why today is bad: pollen and pollution arrive from somewhere.
Ventusky. The same idea with a different model behind it and layers for dust and particulates, useful for seeing weather blown in from a long way away.
Weawow. Plain, ad-light and free, drawing on public forecast data. The one to keep if you want the essentials without an account.
Medisafe. Antihistamines work best taken before exposure rather than after symptoms start, and a reminder set for the season is the difference between the two.
Daylio. A two-tap daily log. Kept for one season alongside the pollen figures, it shows which pollen type your symptoms actually track, which no app can tell you in advance.
Google Home. If there is a purifier or a fan on the network, this is where you schedule it to run before you get home rather than after.
Xiaomi Home. The equivalent for that manufacturer's purifiers and sensors, and its indoor particulate readings are genuinely useful next to an outdoor forecast.
Tuya. Covers a very wide range of unbranded purifiers and sensors, which is often what is actually plugged in at home.
A day in the middle of the season
- Check the type, not the total A high total driven by tree pollen is irrelevant if grass is your problem. Every serious pollen app breaks it down; the general weather apps usually do not.
- Take the antihistamine before you go out This is medication timing rather than an app feature, and it is the single largest thing on this list. Ask a pharmacist how far ahead yours needs to be taken.
- Shut the windows when the wind turns Counts are usually highest in the morning and again in the evening, and a wind map explains a bad day better than the count alone.
- Change what you can after coming in Showering and changing clothes removes the pollen you carried home. Drying washing indoors on a high day stops you bringing in more.
- Log how you felt for one season One line a day. At the end of the summer you will know which forecast to believe and which weeks to prepare for next year.
What a phone genuinely cannot tell you
No phone measures air. Every figure in every app on this list comes from a monitoring station, a satellite or a model, and the app's job is presentation. That is not a criticism; it does mean two apps disagreeing by a small margin are not one right and one wrong, they are two interpolations of the same sparse data.
Indoors is a separate question and the one people ask least. An inexpensive particulate sensor tells you more about the room you sleep in than any outdoor forecast does, and it is the measurement that actually changes behaviour: it shows what cooking, a candle or an open window does to the air you spend eight hours breathing.
None of this is medical advice. An app is for timing and for pattern spotting. If symptoms are getting worse year on year, or a rescue inhaler is being used more than it used to be, that is a conversation with a doctor rather than a better forecast.
One app that breaks pollen down by type, one that reports air quality with its source shown, and a reminder to take the antihistamine early. The rest is windows and washing.
Frequently asked questions
Which pollen number should I be looking at?
The type that affects you, which for most hay fever is grass. Tree pollen peaks earlier in the year and weed pollen later, so a single total hides the thing you need to know.
Why do two air quality apps show different numbers for my street?
Because they use different source stations, different models and sometimes different national scales. Treat small differences as noise and look at the shape of the day instead.
Does an air purifier help with hay fever?
Indoors, a filter that captures fine particles will reduce what is in the room, which is why the bedroom is the place people notice it. It does nothing about pollen you walk through outside.
Can a phone measure air quality directly?
No. It has no sensor for it. Everything shown comes over the network from stations and models, so a phone with no signal has no air quality data at all.
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