Rialto pollen forecast - today, tomorrow and the week ahead

Currently, there is no significant pollen in Rialto.

On 26 June 2026, pollen conditions in Rialto will be similar to today with no significant pollen expected.

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

On 25 June 2026, there are no significant pollen types in Rialto.

Rialto's pollen season opens with acacia and native oak from January in the mild Inland Empire climate. Sycamore and grass follow through March and April, with the season peaking earlier than most US cities. The Lytle Creek corridor and the San Bernardino Mountain foothills channel airflows and concentrate pollen, while surrounding Inland Empire chaparral contributes substantial scrub pollen. Santa Ana winds can concentrate pollen across the area under offshore conditions.

The Rialto 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 Rialto, 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.