Back to blog

Tree Pollen Season Can Be The Worst!

For most areas, spring tree pollen season is the season with the highest pollen concentrations. It is also the season with the highest number of allergy sufferers. Pollen comes from flowers, but the trees producing the major pollen types have flowers that most people wouldn’t recognize.

October 5, 2025 Pollen Sense View production source
Tree Pollen Season Can Be The Worst!
Worker trimming a tree during pollen season.

For most areas, spring tree pollen season is the season with the highest pollen concentrations. It is also the season with the highest number of allergy sufferers. Pollen comes from flowers, but the trees producing the major pollen types have flowers that most people wouldn’t recognize.

Know what to look for.

The flowers of the worst offenders are specifically designed to use the wind to spread their pollen. Birch, elm, oak, cedar, poplar, and olive are examples of trees with flowers designed to spread pollen in the wind. There are many other spring pollen sources and the main sources in your area will be listed in your pollen count feed.

Showy flowers are not the problem.

In many areas, the tree pollen season start is timed with the blooming of ornamental trees. This has caused many people to believe that the beautiful flowering trees like cherry, pear, and others are the cause of the pain. This is almost never the case. A simple rule of thumb is that showy pretty flowers are trying to attract bees and other pollinators because they need them to move the pollen to other flowers.

More from Pollen Sense

A clearer, more helpful Pollen Wise home screen

We’ve been spending a lot of time reviewing feedback, reading survey responses, and looking closely at how people are using Pollen Wise. One common thread amongst the feedback and survey responses stuck out: people want the app to feel easier to understand at a glance, and more helpful in answering the question, “What should I care about right now?” That thinking shaped this latest update. This is a major refresh to the Pollen Wise home screen, and while we know there is still more to improve, this update is an important step. We’re continuing to build, refine, and learn, and your feedback is a big part of what helps us decide where to go next.

Incoming: Branches, Revisions, and Layers

Update: The data cutoff for legacy metrics data was changed from March 11 to March 23, 2026 6PM UTC. Data before that date will continue to be available for the forseeable future, however data after March 23, 2026 6PM UTC will no longer be present either in the legacy portal data viewer or via v1 APIs. Please use the V2 APIs and the Branch/Revision-powered data viewer in the portal for live incoming data

LLMs vs CNNs: Why Physical AI Starts With Data Infrastructure

When we say “AI” at Pollen Sense, most people assume we mean LLMs. We don’t. When people hear that Pollen Sense is building AI data infrastructure, the default assumption is usually large language models, chatbots, text generation, or conversational AI. That’s understandable given the moment we’re in. But it’s not what we mean when we say AI. At Pollen Sense, AI data infrastructure means Physical AI, machine learning systems that directly observe the real world, classify physical signals in real time, and convert them into structured, trustworthy data that other systems can reason on.

Take a Deep Breath

Real-time particulate intelligence for public health, research, and daily life.

Whether you need a sensor network, licensing, or a better allergy experience, the same Pollen Sense infrastructure powers it.