Pollen in the Willamette Valley is causing oppressive conditions for allergy sufferers, with the southern Willamette Valley from the coast to Bend experiencing the most extreme pollen conditions.

Eugene recorded its highest grass pollen count over the past 10 years Tuesday. In Salem and Mid-Willamette Valley, the pollen conditions were somewhat better, with Pollen.com reporting an allergy forecast of 9.2, or "medium-high," while the southern Willamette Valley from the coast to Bend had a "high" rating of 9.8. The pollen conditions are forecast to worsen slightly Wednesday.

The main contributors for the pollen conditions in the Willamette Valley are due to grass and juniper tree pollen, Pollen.com reported. The website's measurement system takes into account how much pollen a person with allergies would likely be exposed to on that day.

The 24-hour grass pollen count Tuesday was a "very high" rating of 1,545, meaning the Eugene-based Oregon Allergy Associates counted that many pollen grains per cubic meter over a 24-hour period. The "very high" category starts when the density is more than 200 grains per cubic meter.

In recent years, the highest grass pollen count has come earlier, usually between Memorial Day and the first week of June, but came later this year due to the frequent rain, said registered nurse Judy Moran with Oregon Allergy Association.

While the damp and rainy weather has suppressed the grass pollen counts this summer, it also contributed to Tuesday's much higher count. A day of sunshine encourages growth from plants primed by the wet weather.

Oregon Allergy Associates, which cares for allergy, asthma and immunology patients, started tracking pollen counts 20 years ago and provides pollen counts to a scientific database for the National Allergy Bureau.

According to Oregon Allergy Associates records, one day in 2012 recorded its highest pollen count of 1,851, and on another in 2009, it was 1,596. Those were the only two days with a higher count, according to Moran.

Residents should be careful to not just go by the daily pollen counts, Moran said, noting that if it's sunny out it might not matter if the pollen count was low for that day.

"Even though the 24-hour count might not reflect it, if you're sitting at a baseball game at three in the afternoon and the wind is blowing, you're going to get a lot of exposure and symptoms," Moran said Tuesday.

After several months of consistent damp weather, the Willamette Valley is forecast to have sunshine and warm weather the rest of this week, with highs getting up to the low 90s on Saturday, according to the National Weather Service.

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Moran said she anticipates pollen conditions improving over the next few weeks, as farmers begin to harvest grass seed, which would reduce the amount of grass pollen spreading.

"I have a couple of neighbors who are farmers, and with the projected warmth, I think a lot of people will start their grass harvest," Moran said. "You still will see pollen, but the fields are going to be knocked down."

Tree pollen count was "moderate" in Eugene on Tuesday, measuring in at 53. Tree height of pollen season varies depending on the kinds of trees, but Moran said the most allergy-inducing trees' pollen season runs from February to early May.

Moran, who tracks the counts, added that residents can minimize their allergies by staying indoors to reduce pollen exposure, and making sure to close their car windows when driving. Even if the conditions become damp and rainy, being in close proximity to a tree producing pollen will still impact those with allergies, Moran said.

There are also simple steps you can take to limit your exposure to the pollen or molds that cause your symptoms:

Source: American Academy of Allergy, Asthma, and Immunology

Louis Krauss covers breaking news for The Register-Guard. Contact him at lkrauss@registerguard.com and follow him on Twitter @LouisKraussNews.