Spring doesn’t officially arrive until March 20, but if you’ve already started sneezing or feeling itchy, you’re not imagining it. A few mild temperature days are enough to kick allergy season into gear.

Dr. Rachel Schreiber, an allergist based out of Rockville, Maryland, says pollen shows up fast once temperatures start to rise.

“The second it gets warm is the second the pollen comes out. It is a simultaneous process,” Schreiber said.

So even if you don’t feel terrible yet, she said allergy season has already started.

With the recent warmer weather, Schreiber said the first wave of tree pollen is already circulating.

“The early pollinators, those trees that are out now, are the maples and the elm tree pollens,” she said. “Oak tree pollen accounts for 50% of the tree pollen in our area.”

As spring moves along, stronger allergens arrive and symptoms often ramp up.

Schreiber said grass pollens follow later, which is why allergy season can feel long and relentless.

“Spring can be very, very difficult for some people,” she said.

Why symptoms can hit you so quickly

If allergies seem to come out of nowhere, Schreiber said there’s a reason — your body remembers.

“You want to get on your allergy medications this instant, because what happens with the body is when you start to have an allergic reaction, your body is actually primed from the year before,” she said.

One way to tell allergies apart from a cold is itchiness.

“Itching — it is the number one symptom of allergy,” Schreiber said. “That could be itching in your upper airway, itching in your eyes, ears, throat, the roof of your mouth.”

But if you’re running a fever, that usually points to something else.

“The thing that does not happen with allergy, (but) does happen with infection, is fever,” she said.

What you can do to make allergy season easier

Schreiber said starting allergy medication early can help keep symptoms from snowballing, but daily habits matter, too.

“If you have allergies and you open your windows, you are letting that pollen right in your house,” she said.

Pets can also track pollen indoors after spending time outside.

“You’re bringing your dog inside, and now your dog is bringing the pollens on their fur, on their paws,” Schreiber said.

“So you want to wipe your pet down, wipe all the fur, wipe all the paws, so you’re not spreading more pollen around the house.”

Timing also matters when you head outdoors.

“The pollens are generally worse in the morning, between 4 a.m. and noon,” she said.

While spring may still be days away on the calendar, Mother Nature follows her own, so allergy sufferers need to act now.