Los Angeles pollen forecast — Westchester HS's Baseball Diamond neighborhood

On 20 July 2026, overall pollen levels in Los Angeles are low. Grass is the main contributor to airborne pollen, while ambrosia and cypress remain at lower levels

On 21 July 2026, pollen conditions in Los Angeles will be similar to today, with grass at low levels, ambrosia at low levels, cypress at low levels

According to the five-day outlook, grass and cypress pollen levels are expected to gradually decrease, while ambrosia and artemisia pollen will increase, suggesting mixed conditions later in the week.

On 20 July 2026, Grass is the dominant pollen source in Los Angeles. ambrosia and cypress are also present but at lower levels. oak, willow, alder, artemisia, and birch are not currently active.

At Westchester HS's Baseball Diamond, a baseball venue in Los Angeles, the pollen season opens with olive and acacia from January with eucalyptus following close behind through February. Grass pollen builds through March and April, and mugwort extends exposure into September. Mild year-round temperatures push the pollen calendar earlier than in most of the country throughout the year.

The Los Angeles 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 Los Angeles, 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.