Juniper
Utah juniper covers close to a fifth of the state's land, at elevations of about 4,000 to 7,500 feet. USU Extension The juniper and cypress family sheds heavy pollen, and reactions to it are often severe. Aerobiologia
Pollen
Pollen along the Front
Trees in spring, grasses in early summer, weeds into fall. Here is when local pollen runs, where to find a measured count, and what helps.
The pollen year
Hay fever tends to come in three waves: tree pollen in early spring, grass pollen in late spring and early summer, and weed pollen in late summer and fall. AAAAI
Intermountain Health gives a rough schedule. Trees run March through June. Grasses run June through August, sometimes into September in a warm year. Weeds run from August through the end of October, until a hard freeze. November to early February usually brings some relief. Intermountain Health Tree pollen can start as early as late February. University of Utah
The calendar below goes plant by plant. It is read from a published calendar of daily averages at the certified pollen station in Draper, for the years 2003 to 2017. Aerobiologia
| Pollen | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Elm | January: little or none | February: in season | March: peak | April: some | May: little or none | June: little or none | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Juniper | January: little or none | February: some | March: in season | April: peak | May: in season | June: some | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Cottonwood | January: little or none | February: some | March: in season | April: in season | May: little or none | June: little or none | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Box elder, maple | January: little or none | February: some | March: some | April: peak | May: in season | June: some | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Mulberry | January: little or none | February: little or none | March: some | April: in season | May: peak | June: some | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Oak | January: little or none | February: little or none | March: some | April: in season | May: in season | June: in season | July: little or none | August: little or none | September: little or none | October: little or none | November: little or none | December: little or none |
| Grasses | January: little or none | February: little or none | March: little or none | April: some | May: in season | June: peak | July: in season | August: in season | September: in season | October: some | November: little or none | December: little or none |
| Amaranth family | January: little or none | February: little or none | March: little or none | April: little or none | May: some | June: in season | July: in season | August: peak | September: in season | October: some | November: little or none | December: little or none |
| Sagebrush | January: little or none | February: little or none | March: little or none | April: little or none | May: little or none | June: little or none | July: little or none | August: some | September: peak | October: in season | November: little or none | December: little or none |
- Some
- In season
- Peak
How to read it. "Some" means pollen showed up on at least a third of the days, or on most days in trace amounts. "In season" means pollen on most days. "Peak" marks the month that was clearly heaviest for that plant. Cottonwood and oak had no single standout month, so they have no peak. A blank month had little or none. The "Amaranth family" row is the group that includes Russian thistle, described below.
Treat it as a guide, not a schedule. Across all the stations in the study, the start of a plant's season typically shifted from year to year by about a week for ragweed and about a month for elm. Pollen timing also depends on temperature, so places warmer or cooler than Draper, such as the higher valleys around Heber and Park City, may not follow this calendar closely. Aerobiologia
Where these levels come from
Lo and colleagues published a color-coded calendar of daily average pollen for each plant group at the Draper station. Aerobiologia HiveWatch read that chart month by month to set each level. No raw counts were used, and the levels are our reading of the chart, not the authors' own labels.
In an average year the station sampled from about early March to mid-October, and not every day. Aerobiologia So the February readings rest on fewer years of data. The authors note that at some stations, juniper-family pollen is already in the air when sampling begins, so its early weeks can be missed. Aerobiologia The chart counts all maples (Acer), box elder included, as one group, and does the same for the amaranth family (Amaranthaceae). Plants below a minimum yearly amount were left off the chart. Aerobiologia
What's in the air
Showy flowers rarely cause hay fever. Their pollen travels on insects. The trouble comes from plants whose powdery pollen spreads easily on the wind. AAAAI These are the main ones on the Draper calendar and in local yards and foothills.
Siberian elm
Planted all over Utah in yards and windbreaks, and it often seeds itself in where nobody planted it. USU Extension Elms release large amounts of allergenic pollen in early spring. Aerobiologia At Draper, elm was the first heavy tree pollen of the year. Aerobiologia
Cottonwood
Fremont cottonwood is Utah's largest deciduous tree, found along low-elevation streams and in moist valley bottoms. USU Extension Pollen counts lump cottonwoods with poplars and aspens. Aerobiologia
Box elder
A maple that grows along streams and in wet spots, mostly from 4,000 to 8,000 feet. It flowers from March to May. USU Extension Some maples trigger allergies and some do not. Aerobiologia
Mulberry
Found across the country, and reactions to its pollen are often severe. Aerobiologia At Draper its pollen peaked in May. Aerobiologia
Oak
Gambel oak covers dry foothills and canyon walls from about 4,000 to 8,000 feet and flowers in March and April. USU Extension Most oaks release a lot of pollen. Aerobiologia
Grasses
Lawn grasses such as bluegrass, ryegrass and timothy, plus pasture and hay grasses, make highly allergenic pollen. Aerobiologia Grass pollen is common in most regions, one reason the American Academy of Allergy, Asthma & Immunology (AAAAI) does not recommend moving to escape allergies. AAAAI
Russian thistle
Russian thistle, the tumbleweed, grows on roadsides, fields and disturbed ground and flowers from July to October. USU Extension It belongs to the amaranth family (Amaranthaceae), the group shown on the Draper calendar. NPS The Asthma and Allergy Foundation of America (AAFA) lists it with lamb's quarters and pigweed among common fall pollen weeds. AAFA
Sagebrush and wormwood
Big sagebrush grows in valleys, basins and mountain slopes from 2,500 to 10,000 feet and flowers in August and September. USU Extension AAFA counts sagebrush among common fall pollen weeds. AAFA The Riverton count page labels it "Sage, Wormwood." AAAAI NAB
Ragweed
Ragweeds shed plenty of pollen and are a leading cause of late-summer hay fever. USU Extension It grows nationwide but is most common in the Midwest. Aerobiologia Ragweed did not make the Draper calendar, while sagebrush and the amaranth family did. Aerobiologia
Reading a pollen count
A pollen count is a measurement. A rooftop sampler collects pollen from the air, a certified counter identifies the grains under a microscope, and the result is the average number of grains per cubic meter of air over 24 hours. Aerobiologia AAAAI NAB
The National Allergy Bureau (NAB), part of AAAAI, turns counts into four levels above zero. Each plant group has its own cut-offs. AAAAI NAB
| Level | Tree | Grass | Weed | Mold |
|---|---|---|---|---|
| LevelAbsent | Tree0 | Grass0 | Weed0 | Mold0 |
| LevelLow | Tree1–14 | Grass1–4 | Weed1–9 | Mold1–6,499 |
| LevelModerate | Tree15–89 | Grass5–19 | Weed10–49 | Mold6,500–12,999 |
| LevelHigh | Tree90–1,499 | Grass20–199 | Weed50–499 | Mold13,000–49,999 |
| LevelVery high | Tree1,500 or more | Grass200 or more | Weed500 or more | Mold50,000 or more |
These levels describe how common a count is, not how you will feel. "Low" means below the middle of counts from all certified stations, and "very high" means the top 1%. NAB says the levels are based on what stations measure, not on health effects, and a few stations set their own local ranges. AAAAI NAB Studies have found mild symptoms at fairly low counts, around 10 to 20 grains per cubic meter. Aerobiologia The Riverton station's page lists mold as not counted, so the mold column is for reference. AAAAI NAB
A count is not a forecast. Counts come from real samples and reflect the weather that day. The predicted "pollen forecast" on many websites is often built from past years' pollen and general weather forecasts, so it is not a measurement of today's air. AAAAI NAB
Where to see a real count
The Wasatch Front's active pollen counter is at Intermountain Health's Southridge Clinic in Riverton, a certified counting station that works with the NAB. Intermountain Health In 2025, KSL reported that an allergist and a certified nurse read the sampler's tape under a microscope at least three times a week, and that Riverton-area counts are posted three days a week. KSL
As of October 24, 2026, the newest report on the station's page was from October 15. AAAAI NAB Most stations in the national study of 2003 to 2017 did not count year-round. Aerobiologia
NAB treats one collector as covering up to about 50 miles in normal conditions, but mountains, wind, rain, buildings and nearby plants all change that. AAAAI NAB Riverton is in the Salt Lake Valley, so its count fits there best. For Utah, Davis and Weber counties and the higher valleys, read it as a rough guide, not a local reading.
KSL also reported that NAB showed a second Utah counter, at an urgent care center in Draper. KSL A Utah station page on NAB labeled Salt Lake City showed nothing newer than April 2023 as of October 24, 2026. AAAAI NAB
We found no free, official pollen forecast for Utah. The Utah Division of Air Quality (DAQ) forecast covers air pollution only, Utah DAQ and the state asthma program's pollen page offers general advice without local counts. Utah DHHS
HiveWatch links to the count instead of copying it, because NAB does not allow its counts to be reused without written permission. AAAAI NAB
- Riverton pollen count (AAAAI NAB)https://pollen.aaaai.org/#/station/52f56692-d06d-44a8-a86c-dee9ca9157fe
- Intermountain Southridge Clinic allergy pagehttps://intermountainhealthcare.org/locations/southridge-clinic/allergy
- How NAB sets its levelshttps://pollen.aaaai.org/#/pages/reading-the-levels
Pollen on bad-air days
Pollen and pollution add up. Air pollutants can make pollen grains more allergenic. AAAAI ranks ozone, a gas that forms in sunlight, among the pollutants most likely to set off asthma attacks. It notes that asthma symptoms may worsen even when ozone is in the Moderate range. AAAAI
In Utah, ground-level ozone is usually highest from noon to 8 p.m., May through September. Utah DEQ Those are the same months as grass and weed pollen on the calendar above. Ozone forms when other pollutants react in sunlight and heat, and it is especially hard on people with asthma and people who work outside. Utah DEQ
The Air Quality Index (AQI) does not include pollen. It is built from five pollutants: ozone, particle pollution, carbon monoxide, sulfur dioxide and nitrogen dioxide. AirNow A Good AQI day can still be a heavy pollen day. On summer afternoons, check both: the AQI under Today on the home page, and the Riverton count. See what to do when the AQI climbs.
Cutting your exposure
- Close up during your season. Keep windows shut at home and in the car, and use air conditioning. Skip window fans, which can pull pollen inside. ACAAI
- Rinse it off. After time outside, shower, wash your hair and change clothes. AAAAI Keep your hands away from your eyes until you have washed them. CDC
- Dry laundry indoors. Pollen can cling to sheets and towels on the line. ACAAI
- Filter what you can. Use a furnace filter rated at least MERV 13, or as high as your system can take. EPA A portable HEPA air cleaner may help. Studies found gains in some allergy and asthma symptoms, though not all. Avoid air cleaners that make ozone on purpose. EPA Prepare Utah covers setting up filters for the home.
- Hand off the mowing, or mask up. Mowing and raking stir up pollen. If your symptoms are bad and you can't avoid long yard work, a pollen mask can cut what you breathe. AAAAI Masks help partly, not completely. University of Utah If you have heart or lung disease or are pregnant, ask your clinician about masks.
- Watch the weather more than the clock. Pollen moves less on rainy, cloudy or still days and more on hot, dry, windy ones. AAAAI Sources disagree on the worst hours. ACAAI says midmorning and early evening, and that it varies by plant. ACAAI AAAAI says grass tends to run highest early morning and early evening, and other pollens midday and afternoon. AAAAI Utah's asthma program says most pollen is released from 11 a.m. to 4 p.m. Utah DHHS
- Start medicine before the season, with your clinician. Most hay fever medicines work best if started before pollen arrives. AAAAI Intermountain Health suggests starting about a month before your season. Intermountain Health Ask your clinician which medicine fits you and when to start.
Storms and food
Thunderstorm asthma
Rain usually clears pollen, but a thunderstorm can do the opposite. Updrafts carry grass pollen into wet clouds, the grains burst, and downdrafts bring the fragments back down. The pieces are small enough to reach the lungs. AAAAI
This can bring on asthma even in people who have only had nose and eye allergies. Some weed pollens and molds can do it too, especially in a storm's first 20 to 30 minutes. If you have seasonal or mold allergies, AAAAI suggests going inside and shutting the windows before a strong thunderstorm arrives. AAAAI
Itchy mouth after fruit
Some people with hay fever notice an itchy mouth or throat after eating certain fruits or vegetables raw. This is called oral allergy syndrome, or pollen food allergy syndrome. Most people can eat the same foods cooked. ACAAI
Common pairs: grass pollen with celery, melons, oranges, peaches and tomato, and ragweed with banana, cucumber, melons, sunflower seeds and zucchini. If a reaction ever goes beyond your mouth, see an allergist and ask whether you need epinephrine. ACAAI
When to get care
See a clinician, often an allergist, when:
- Symptoms show up most days. They wear you out, cost you sleep or make you miss work. University of Utah
- Over-the-counter medicine isn't working. Or your allergies come with coughing or wheezing. Intermountain Health
- Symptoms last many months of the year. An allergist can find your triggers and may suggest allergy shots, which often give lasting relief. AAAAI
Asthma emergencies
If you have asthma, follow your asthma action plan. Call 911 if your medicines are not relieving an asthma attack or breathing is still very hard. NHLBI
For a young child with asthma, call 911 if the child seems drowsy, confused or troubled, has a blue tint to the lips or skin, or has a fast heartbeat. NHLBI
Longer seasons
A University of Utah-led study of 60 pollen stations in the U.S. and Canada found that, compared with 1990, seasons by 2018 started about 20 days earlier, lasted about 10 days longer and carried about 21% more pollen. Human-caused climate change could account for about half of the longer seasons and about 8% of the extra pollen. The biggest increases in pollen were in Texas and the Midwest. University of Utah The only Utah station in that study was in Draper, so it says little about trends in northern or southern Utah. KSL
Salt Lake City's freeze-free season, the stretch between the last spring freeze and the first fall freeze (32°F), grew by about 24 days from 1970 to 2025, based on the long-term trend in Climate Central's city data. Climate Central That is a temperature measure, not a pollen count. More frost-free days can shift when pollen season starts and ends and how much pollen plants make. CDC
One year, not a trend. March 2026 averaged 53.6°F at Salt Lake City's airport, the warmest March in a record that starts in 1929. NOAA ACIS Because pollen timing follows temperature, a spring that warm can bring trees into season earlier than the calendar above shows. Aerobiologia
Checked October 24, 2026.