(CBS) — This is already shaping up as a challenging spring allergy season for many people.

Dr. Joseph Leija, an allergist at Gottlieb Memorial Hospital in Melrose Park, said tree pollen counts have been very high in the past week; causing a lot of sneezing, itchy, and watery eyes, and even some headaches.

He takes pollen readings on the roof of the hospital most mornings between April and October.

“It’s going to be a rough season,” he said.

However, days like today — with some rain and cooler temperatures — are good for people with spring allergies.

“It washes everything down for a while,” Leija said.

But then as the temperatures start to warm and the wind starts blowing again, “you start to have trouble again.”

Leija said you should not skip taking allergy medicines on days when you don’t think pollen counts will be high. Those medications need one to three days to build up in your system, so that your body is prepared when pollen counts climb again.