(NEXSTAR) – Spring has sprung and you may be starting to get early signs of the sniffles. But there's bad news for allergy sufferers: The worst is still to come. Multiple allergy forecasters indicate 2025 is likely to be a pretty rough year for seasonal allergies. Pollen counts are ex pected to be higher than average in 39 states, predicts Alan Reppert, a meteorologist with AccuWeather. If you're stocking up on antihistamines and bracing for impact, AccuWeather put together three maps showing when common allergens are expected to peak across the continental U.S. Allergy sufferers in these US cities face a tough 2025 season, study finds Tree pollen is usually the first culprit to arrive on scene, and it may already be starting to irritate you sinuses. Peak tree pollen season comes soonest to the southern states, around early April, before making its way northward through the start of June. Grass pollen is up next, peaking between May and July depending on where you live. Residents of the Pacific Northwest and New England can expect the worst when it comes to grass pollen, according to AccuWeather's forecast. Before you can catch a break, here comes weed pollen, causing issues from mid-to-late summer. Things are expected be roughest for the weed-allergy sufferers in the southern and Gulf states. It could be even worse if we have an active period of tropical storms and hurricanes, which tends to extend the extend the weed pollen season, according to AccuWeather. Nationwide, allergy season is growing longer and more severe. Of the nearly 200 cities studied by Climate Central, the researchers found 87% have seen allergy season worsen since the 1970s. The biggest changes have happened in the Northwest and Southwest. Much of the change can be attributed to a warming climate, according to Climate Central. The earlier arrival of spring and warmer temperatures stretch out growing season, giving trees, weeds and grass more time to prosper and release pollen. It’s not just that allergy season is growing longer – there’s also evidence it’s getting more intense. One study looked at the impact of increased carbon dioxide on ragweed plants. It found that with more carbon dioxide in the environment, ragweed plants grew larger and produced significantly more pollen. ...read more read less