Idaho Allergy Season: Peak, Timing, and Symptoms

Written by Andrew Wood
Updated: April 23, 2023
© Kirk Fisher/
Share this post on:

Idaho is world-famous for its unspoiled natural beauty, but for allergy sufferers, pollen from fields and forests can make it hard to enjoy this gorgeous state as much as you’d like. Whether you’re a citizen of Idaho or planning a visit there, this article is a must-read to find out the Idaho allergy season peak, timing, and symptoms. You’ll also find information about what causes allergies, how to prevent and manage symptoms, and how to protect your pets as well. Along the way, we’ll tell you whether dogs can be allergic to cats, whether pets can take people allergy meds, and even show you how to save money on over-the-counter medication.

Salmon-Challis National Forest in Idaho
Idaho’s unspoiled natural beauty is legendary and well worth the trip to see.

© Intermountain Forest Service, USDA Region 4 Photography / Flickr – License

What are Allergies?

Allergies are the result of the immune system reacting to things that are actually harmless as if they were hostile threats to the body. These allergens can include types of food, pet dander, chemicals, and often pollen from trees, shrubs, flowers, and grasses. Coming in contact with an allergen, a sensitive immune system releases chemicals such as histamine to combat it. This results in symptoms like breaking out in hives or itchy rashes, coughing, congestion, sneezing, etc. Allergies are no laughing matter. The most severely allergic people can go into anaphylaxic shock, which, if not treated immediately, can restrict breathing and lower blood pressure, resulting in brain injury or death.

Over time, an individual might notice a change in their allergies. Children sometimes outgrow allergies. Adults might develop new allergies. Older adults may discover allergies to new medications they did not need when they were younger. In some cases people do develop a tolerance to certain allergens through repeated exposure, but not always.

Treating Allergies

Treating allergies at home is fine if the symptoms are mild. There are some really effective medicines on the market you can buy over the counter. Later in this article, we’ll provide links to generics of some of the most popular of these to save you some money. If allergies are severe, the patient may choose to start immunotherapy, in which regular injections of an allergen are administered to build up immunity to it.

If your allergies are severe and left untreated, you could develop complications such as sinusitis – a chronic inflammation of the sinuses; ear infections from fluid buildup in the ears; sleep disturbances; skin infections from rashes, or worsening of asthma symptoms and frequency of attacks. It is important to see your doctor if your symptoms are not managed well with over-the-counter medications so you can prevent any of these complications from developing.

Woman with allergy symptoms
Allergies can become better or worse as we get older, depending on a lot of different factors unique to the individual.


When is Idaho Allergy Season Most Troublesome?

Because it has so much rugged, mountainous terrain, Idaho has a lot of variety in its climate and vegetation. It’s actually warmer than nearby states like Montana and Wyoming because its high mountains protect it from some of the cold winter air currents coming down from Canada. Parts of it are in the rain shadow of mountains to the west, so it can be extremely dry there. On the other hand, in the Northern Rocky Mountains, precipitation is quite high. The kinds of vegetation, and the allergens they produce, will differ depending on where in the state you are and at what elevation.

Here are some of the kinds of allergens you may encounter in Idaho and the peak season for each:

  1. Mountain cedar (Juniperus ashei) – From late November to early February.
  2. Oak (Quercus) – From late March to early May.
  3. Birch (Betula) – From early April to mid-May.
  4. Grasses – Several types of grasses are common allergen sources in Idaho, including Timothy grass (Phleum pratense), Kentucky bluegrass (Poa pratensis), and Bermuda grass (Cynodon dactylon). The pollen season for grasses typically runs from late spring to early fall.
  5. Ragweed (Ambrosia) – From late July to early October.
  6. Sagebrush (Artemisia tridentata) – From late summer to early fall.

What is Pollen Count?

Pollen count is a measure of the number of grains of pollen in a cubic meter of air. You can find out the pollen count in your area each day during allergy season by watching local weather, consulting a pollen forecast website, or a local meteorological office. Pollen counts differ from day to day based on all sorts of factors, like humidity and precipitation, wind speed and direction, and temperature. This means pollen forecasts may not be entirely accurate, but they can give you a general guide so you can make any adjustments you’d like to your plan for outdoor activities each day.

Allergy Season
On high pollen days, you may want to adjust your plans to avoid outdoor activities.

©Chad Robertson Media/

How Can You Be Tested for Allergies?

Over time, you may have figured out what you’re allergic to by just noting when and where they happen and what you were doing at the time. The only way to be really sure, though is to see an allergist. This is something you should definitely do if you are having severe symptoms and don’t know what is causing them. Once you know, you will be able to take some preventative steps to avoid known allergens and make your life a lot easier.

An allergist will typically apply drops of liquid with concentrated allergens on the skin of your arm or back. They will often apply 10 or so different common allergens, scratch them lightly with a needle to get the allergen under the skin, and then look at the area to see which of these may have caused the skin to turn red and inflamed. If none of them create a reaction, you may have another round with less common allergens. Another way to test for allergies is through a blood test. This can tell if your body has created antibodies in an allergic reaction. This test is not considered as accurate as a skin test.

Negative Result with Symptoms

Sometimes a patient will have allergy symptoms but still have a negative allergy test. Some of these cases are diagnosed as non-allergenic rhinitis. In this situation, the body produces an allergic reaction but no allergen is identified. The reaction could be coming from a viral infection, exposure to smoke, chemicals, or strong odors such as perfumes or air fresheners, hormonal changes, or certain kinds of medication. It can also be caused by physical issues such as a deviated septum, contributing to inflammation. Surgery can sometimes help these kinds of structural issues. For the others, antihistamines, decongestants, and nasal sprays may provide relief, as well as avoiding anything that seems to make the symptoms worse.

Allergy Test
Skin testing is considered a safe and accurate way to determine what a person is allergic to.


Preventing Allergies

The best way to manage allergies is to prevent them from happening in the first place. Some ways you might do this include:

  • Removing from your home and office any known allergy sources, as much as possible.
  • Limiting pets to separate areas of the house, if you are allergic to them. Especially don’t let them sleep on your bed.
  • Regularly washing curtains, sheets, blankets, and pet bedding in hot water to kill dust mites.
  • Wear a mask outdoors during peak allergy season.
  • Keep doors and windows closed and use your air conditioner
  • Consider investing in a HEPA-filtered air purifier. You might want to keep it in your bedroom at night.
  • Keep your house clean with frequent vacuuming and dusting. Use a microstatic dusting cloth to remove the dust rather than just stirring it up.
  • Wash your hands frequently and don’t touch your face, as this is where many allergens enter your body.
  • Shower and change your clothes after spending time outdoors.
  • Change your landscaping plan if specific plants, shrubs, or trees are contributing to your symptoms.
  • Manage your stress. High stress can weaken your immune system and make you vulnerable to a whole host of medical problems, including allergy symptoms. Explore breathing exercises, prayer, meditation, getting enough exercise and sleep, taking breaks from work, and eating a good diet.
dust mite
You can fight dust mite allergies by washing bedding in hot water to kill them.


Best Over-The-Counter Allergy Treatments

If you’ve struggled with allergies for a while, you probably already have your favorite medications that bring you relief. But did you know that most of the name brands now have generic equivalents that have EXACTLY the same ingredients at a fraction of the cost? Check out the links below to generics of four popular allergy medicines. Compare these to yours and see if one will work for you . . . and your pocketbook.

Amazon Basic Care Loratadine Antihistamine
  • Long-lasting relief from allergy symptoms
  • Non-drowsy formula
  • Active ingredient is the antihistamine Loratadine (10 mg)
  • 24-hour allergy relief
Check Amazon
ValuMeds 24-Hour Allergy Medicine
  • 24-hour allergy relief
  • Works for pollen, hay fever, dry eyes, itchy eyes
  • Main ingredient is Cetirizine HCl
Check Amazon
ValuMeds Antihistamine, Diphenhydramine HCl 25 mg
  • 600 tablets
  • Active ingredient: Diphenhydramine HCl 25 mg
  • Suitable for Children and Adults
  • Relieves Itchy Eyes, Runny Nose, Sneezing

Check Amazon
HealthCareAisle Allergy Relief - Fexofenadine Hydrochloride
  • Active ingredient: Fexofenadine Hydrochloride
  • 90 tablets of 180 mg
  • Non-Drowsy
  • 24-Hour Allergy Relief

Check Amazon

Of course, you know this, but it bears repeating: follow the dosage instructions on the label, be alert to potential side effects or reactions, and consult a healthcare professional about any possible interactions with other medicines you are taking.

Allergy sufferer
Over-the-counter allergy medicines can be a lifesaver in high-allergen environments.


What if Your Pet Has Allergies?

Pets can suffer from some of the same kinds of allergies as people. In fact, did you know that dogs can even be allergic to cats?! More typically, pets may be allergic to an ingredient in their food, such as the type of protein or grain used in their kibble or some other additives. Your vet might recommend lamb and rice formula for a dog with food allergies. Pets can also be allergic to flea bites, dust mites, and mold. Excessive scratching, biting at the skin, licking the paws, and grooming can be tell-tale signs of allergies in a furry pet. You might even notice the animal starting to develop bald places and inflamed skin from worrying with it so much. Pets can also manifest allergies in coughing, sneezing, or respiratory problems. Your vet may want to treat the issue with dietary changes, environmental changes, medication, or even immunotherapy.

Cat licking its paws
Obsessive grooming can be a sign of allergies in a pet.

©Fayzulin Serg/

Can Pets Take Human Allergy Medicine?

Yes, pets can take some human allergy medicines but not all. Some that work for certain kinds of pets, such as dogs, might be ineffective or even fatal for cats. The dosage of the medication must be regulated according to the species, weight, and overall health of the pet. All of this means, of course, consult your veterinarian before administering any medication to your animal.

Being aware of what causes allergies, how to prevent and treat them, and how to guard your pet as well . . . you should be well on your way to your next adventure in Idaho.

spay a dog at petsmart
Consult your vet before medicating your animal. Better safe than sorry.


Up Next:

More from A-Z Animals

The Featured Image

Lake Pend Oreille
Lake Pend Oreille is a beautiful lake in Idaho.
© Kirk Fisher/

Share this post on:
About the Author

I'm a freelance writer, world traveler, and lifelong animal lover. Currently, I'm an "Emotional Support Human" to 4 dogs, 1 cat, and 2 guinea pigs. My favorite wild animal is the quokka, the most selfie-friendly animal in the world!

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.