Portland pollen forecast — Slabtown neighborhood

Currently, there is no significant pollen in Portland.

On 17 July 2026, pollen conditions in Portland will be different from today, with ambrosia at low levels, grass at low levels

According to the five-day outlook, ambrosia, artemisia, and grass pollen levels will increase later in the week.

On 16 July 2026, there are no significant pollen types in Portland.

Slabtown, a neighborhood in Portland, opens its pollen season with alder and birch from February with maple taking the lead through March and April. Grass pollen rises through May and June, and mugwort and nettle extend exposure into September. The damp, mild regional climate keeps pollen counts lower than in drier parts of the country, though spring rain events can trigger brief spikes, a defining feature of the local season.

The Portland pollen forecast is updated four times daily. See the timestamp below for the most recent update.

Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.

Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.

Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in Portland, modern forecasts combine recent measurements, weather data, and information about local vegetation.

This allows us to estimate pollen levels for today and the coming days, not just report the past.

Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.