Cedar fever is an intense allergic reaction to pollen from mountain cedar trees (Juniperus ashei), not a virus or infection. Despite the name, it rarely causes an actual fever. It hits hardest in Central Texas from December through February, affects up to 20% of Texans, and can trigger severe cold-like and flu-like symptoms, even in people who’ve never had seasonal allergies before. Below is everything you need to know: what causes it, what it feels like, when it peaks, and exactly how to treat it.
What Is Cedar Fever?
Cedar fever is a type of allergic rhinitis , an overreaction of your immune system to pollen released by mountain cedar trees. When you inhale cedar pollen, your body identifies those tiny grains as a threat and floods your system with histamine and other inflammatory chemicals. That immune response creates the congestion, fatigue, and misery that feel so much like the flu.
A few important clarifications about what cedar fever is and what it isn’t:
- It is not contagious. You cannot catch it from another person or spread it to someone else. It’s an allergic reaction, not an infection.
- It is not caused by true cedar trees. The culprit is Juniperus ashei, commonly called Ashe juniper or mountain cedar , a species of juniper, not a botanical cedar.
- It usually does not involve an actual fever. Some people report a slightly elevated temperature from the intense inflammatory response, but a significant fever (above 101°F) likely signals a cold, flu, or other infection.
- It can affect people who don’t normally have allergies. Because the sheer volume of pollen is so extreme, even people with no prior history of seasonal allergies can develop symptoms during peak season.
According to Karl Flocke, a woodland ecologist with the Texas A&M Forest Service, the pollen from Ashe junipers isn’t particularly allergenic on its own , it’s just so concentrated that your body can’t help but react when millions of trees release pollen simultaneously.
Cedar Fever Symptoms
Cedar fever symptoms closely mimic the common cold and flu, which is why so many people don’t realize they’re dealing with an allergy. The most common symptoms include:
- Nasal congestion and stuffiness, often severe and persistent
- Runny nose, typically with clear (not colored) mucus
- Sneezing, frequent and repetitive
- Itchy, watery, or red eyes
- Sore throat , from post-nasal drip
- Coughing
- Extreme fatigue , one of the most debilitating symptoms
- Headache and sinus pressure
- Partial loss of smell
- Plugged or “full” ears
Some people also experience body aches, mild facial swelling, and a general “brain fog” or difficulty concentrating. If you have asthma, COPD, or other respiratory conditions, cedar fever can worsen those symptoms and trigger wheezing, chest tightness, or shortness of breath.
One useful clue: if your mucus is clear, you’re more likely dealing with cedar fever or another allergy. Colored or thick mucus typically points to a viral or bacterial infection.
Cedar Fever vs. Cold vs. Flu vs. COVID
Because cedar fever hits during cold and flu season, the overlap in symptoms causes real confusion. Here’s a side-by-side comparison to help you tell them apart:
| Symptom | Cedar Fever | Common Cold | Flu | COVID-19 |
| Sneezing | Frequent | Common | Rare | Occasional |
| Itchy/watery eyes | Very common | Rare | Rare | Rare |
| Runny nose | Yes (clear) | Yes (may turn colored) | Sometimes | Sometimes |
| Nasal congestion | Severe | Common | Sometimes | Sometimes |
| Sore throat | Yes (post-nasal drip) | Common | Sometimes | Common |
| Cough | Mild to moderate | Common | Common (dry) | Common (dry) |
| Fever | Rare / very mild | Rare / low-grade | High (101–104°F) | Variable |
| Body aches | Mild (from inflammation) | Mild | Severe | Common |
| Fatigue | Yes, can be severe | Mild | Severe | Common |
| Loss of taste/smell | Partial (congestion) | Partial | Rare | Common |
| Nausea/vomiting | No | Rare | Sometimes | Sometimes |
| Contagious? | No | Yes | Yes | Yes |
| Duration | Weeks (entire season) | 7–10 days | 1–2 weeks | 1–3 weeks |
The biggest differentiators: cedar fever is never contagious, usually involves intense eye itching that colds and flu don’t, and lasts for weeks or the entire season rather than resolving in 7- 14 days.
What Causes Cedar Fever?
The cause is straightforward: mountain cedar pollen in overwhelming concentration.
Central Texas is home to roughly 8.6 million acres of Ashe juniper trees, concentrated in the Texas Hill Country west of Interstate 35. Unlike most trees that pollinate in spring, mountain cedar releases its pollen during winter , triggered by the passage of cold fronts that sweep through the region.
What makes cedar fever so intense is scale. A single mountain cedar tree can release billions of pollen grains. Multiply that by millions of trees all pollinating within the same narrow window, and the result is airborne pollen concentrations so dense they’re sometimes visible , appearing as clouds of “pollen smoke” drifting off hillsides.
Wind carries this pollen far beyond the Hill Country. Strong northerly or westerly winds push cedar pollen into Austin, San Antonio, Dallas-Fort Worth, Houston, and beyond , meaning you don’t need a mountain cedar in your yard (or even in your city) to be affected.
Cedar fever also catches people off guard because winter is not when most people expect allergies. Ragweed and mold spore season tapers off in the fall, and spring pollen hasn’t started. Mountain cedar fills that gap with an intensity that most other allergens can’t match.
Cedar Fever Statistics: How Many People Are Affected?
The numbers put cedar fever’s impact in perspective:
- Up to 20% of Texans , nearly 1 in 5 residents , experience cedar pollen allergies each year, making it one of the most significant seasonal allergy issues in any U.S. state.
- In clinical allergy testing in the San Antonio area, mountain cedar sensitivity shows up in approximately 43% of patients with atopy (allergic tendencies), making it the single top tree allergen in South and Central Texas.
- Central Texas alone contains roughly 8.6 million acres of Ashe juniper, with the densest concentration in the Hill Country west of I-35.
- One mountain cedar tree can release billions of pollen grains in a single season, and the synchronized release from millions of trees creates some of the highest airborne pollen counts recorded for any tree species in the U.S.
- Pollen counts during peak season regularly reach “very high” or extreme levels on standardized scales (9.5–11+ on the NAB scale), routinely triggering symptoms hundreds of miles from the source trees.
- Cities like Dallas and Austin frequently rank among the worst “Allergy Capitals” on the Asthma and Allergy Foundation of America’s annual list, driven in large part by cedar season.
These aren’t small numbers. Cedar fever is a regional public health issue that affects daily life, work productivity, and quality of life for millions of Texans every winter.
Cedar Fever Season: When Does It Start and Peak?
Cedar fever season follows a predictable pattern, though the exact timing and intensity shift from year to year based on weather.
| Month | What’s Happening | Pollen Level |
| November | Earliest mountain cedar pollen may appear after the first strong cold fronts. Most people don’t notice symptoms yet. | Low |
| December | Season ramps up. Pollen counts rise steadily, especially in Central Texas. Symptoms begin for many. | Moderate to High |
| January | Peak month. Mid-January typically sees the highest pollen counts of the season. Massive pollen clouds are visible. This is when symptoms are most severe. | Very High to Extreme |
| February | Pollen production tapers but can still be significant. Symptoms persist for many, especially after windy days. | Moderate to High |
| March | Tail end of the season. Most mountain cedar pollen is spent, and counts drop. Lingering symptoms fade. | Low |
In January 2026, Houston-area pollen counts increased sevenfold in a single week after a cold front, reaching “very high” levels and triggering symptoms across Southeast Texas , demonstrating how quickly conditions can spike.
Key weather triggers: cold fronts, dry conditions, and strong winds all accelerate pollen release and dispersal. A warm, dry winter typically means a worse cedar season. Rainy or humid conditions can temporarily suppress airborne pollen.
Where Does Cedar Fever Hit Hardest?
Cedar fever’s geographic footprint is concentrated in Texas but extends across multiple states:
- Epicenter: Texas Hill Country , The dense concentration of Ashe juniper west of I-35 makes this the worst zone. Cities like Fredericksburg, Kerrville, and Marble Falls sit in the heart of it.
- Austin and San Antonio , Both cities border the Hill Country and consistently see extreme pollen counts from December through February.
- Dallas-Fort Worth , No significant local mountain cedar population, but wind-carried pollen from Central Texas regularly pushes counts into the “high” and “very high” range. Dallas frequently ranks on the AAFA’s Allergy Capitals list.
- Houston , Farther from the source, but strong cold fronts can carry cedar pollen hundreds of miles east into the Houston metro, causing sudden symptom spikes.
- Oklahoma, Arkansas, and Missouri , Eastern redcedar (Juniperus virginiana) and other juniper species pollinate on a similar winter timeline and cause comparable allergic reactions, though at lower concentrations than Central Texas.
If you live anywhere in Texas or the surrounding states and experience unexplained cold-like symptoms every winter that last for weeks, cedar fever is a strong possibility , even if there are no mountain cedar trees near your home.
Cedar Fever Treatment
Treatment for cedar fever follows a tiered approach: start with over-the-counter relief, step up to prescription options if needed, and consider immunotherapy for long-term control.
Over-the-Counter Medications
For mild to moderate symptoms, OTC allergy medications are the first line of defense:
- Antihistamines such as cetirizine (Zyrtec), loratadine (Claritin), or fexofenadine (Allegra) block the histamine response that causes sneezing, itching, and runny nose. Non-drowsy formulas work well for daytime use.
- Nasal corticosteroid sprays like fluticasone (Flonase) or triamcinolone (Nasacort) reduce inflammation in the nasal passages and are especially effective for congestion and sinus pressure. These work best when used daily throughout the season, not just on bad days.
- Decongestants such as pseudoephedrine (Sudafed) provide short-term relief from nasal stuffiness. Avoid using nasal decongestant sprays (like Afrin) for more than three consecutive days, as they can cause rebound congestion.
- Antihistamine eye drops for itchy, watery eyes.
- Saline nasal rinse (neti pot or squeeze bottle) , flushes pollen directly out of the nasal passages. Safe for daily use and effective at reducing symptom buildup.
The most important principle: start medications before symptoms get severe. Taking antihistamines and nasal sprays daily beginning in late November or early December , before peak season , is significantly more effective than waiting until you’re already miserable.
Prescription Medications
If OTC options aren’t enough, an allergist can prescribe stronger treatments:
- Prescription-strength nasal sprays (e.g., azelastine/Astelin)
- Combination antihistamine-decongestants (e.g., Claritin-D, Allegra-D)
- Oral corticosteroids for severe flare-ups (short-term use only)
- Leukotriene receptor antagonists (e.g., montelukast/Singulair)
Immunotherapy (Allergy Shots or Drops)
For people whose cedar fever significantly impacts their quality of life year after year, immunotherapy offers the best chance at long-term relief.
- Allergy shots (SCIT): Small, gradually increasing doses of cedar pollen extract are injected under the skin over months to years, training your immune system to tolerate the allergen. This is the gold standard for long-term cedar allergy management.
- Sublingual immunotherapy (SLIT): Allergen drops or tablets placed under the tongue daily. Same principle as shots but can be done at home.
The catch: immunotherapy takes time. Your immune system needs 6 to 12 months of treatment to build meaningful tolerance, which means starting in late spring or summer for protection by the following winter. If you wait until January to see an allergist, shots won’t help much for the current season.
How to Prevent Cedar Fever Symptoms
You can’t eliminate cedar pollen from the air, but you can reduce your exposure:
- Monitor pollen counts daily using local allergy trackers or apps (AAAAI National Allergy Bureau, pollen.com, or your local news) and limit outdoor time on high-count days.
- Keep windows and doors closed during cedar season , in both your home and your car.
- Shower and change clothes after spending time outdoors to wash off pollen that clings to hair, skin, and fabric.
- Use a HEPA air purifier indoors, especially in bedrooms, to filter pollen particles from the air.
- Dry clothes in a dryer, not on an outdoor line , fabric is a pollen magnet.
- Wear sunglasses outdoors to reduce pollen contact with your eyes.
- Start medications early , begin your daily antihistamine and nasal spray regimen in late November, before the peak hits.
Can You Develop Cedar Fever Later in Life?
Yes. Many people who move to Texas from other states develop cedar fever after a few years of exposure , even if they never had allergies before. This happens because your immune system needs repeated exposure to mountain cedar pollen before it becomes sensitized and starts overreacting.
This also explains why some lifelong Texans develop cedar fever in their 30s, 40s, or later, seemingly out of nowhere. Allergic sensitization is cumulative. Once your immune system crosses the threshold of reactivity, symptoms can appear suddenly and intensify from year to year.
If you’re new to Texas and your first winter felt fine, don’t assume you’re immune. Cedar fever can take two to five years of exposure before symptoms emerge.
When to See a Doctor
Most people manage cedar fever effectively with OTC medications and exposure reduction. But you should see an allergist if:
- Your symptoms are severe enough to interfere with sleep, work, or daily life despite consistent OTC medication use.
- You develop wheezing, chest tightness, or shortness of breath , especially if you have asthma.
- Your symptoms last beyond March or occur outside the typical cedar season (which may indicate additional allergies).
- You’re interested in immunotherapy for long-term relief , and the earlier you start, the better.
- You’re unsure whether your symptoms are allergies, a cold, or something else , an allergist can run a skin prick test or blood test to confirm cedar sensitivity.
Frequently Asked Questions
Q1. What is cedar fever?
Ans: Cedar fever is an allergic reaction to pollen released by mountain cedar trees (Ashe juniper). Despite the name, it is not a virus and rarely causes an actual fever. It produces cold-like and flu-like symptoms , congestion, sneezing, fatigue, itchy eyes , during the winter months, primarily in Texas and surrounding states.
Q2. Is cedar fever contagious?
Ans: No. Cedar fever is an immune response to pollen, not an infection. It cannot be passed from person to person.
Q3. When is cedar fever season?
Ans: Cedar fever season typically runs from December through February, with pollen counts peaking in mid-January. It can start as early as November and linger into March, depending on weather patterns.
Q4. How long does cedar fever last?
Ans: Symptoms can persist for the entire duration of the pollen season , roughly 8 to 12 weeks for most people. Individual flare-ups tend to worsen after cold fronts and windy days that spike pollen counts.
Q5. Can you get cedar fever outside of Texas?
Ans: Yes. Parts of Oklahoma, Arkansas, and Missouri have juniper species that produce similar allergenic pollen on the same winter timeline. However, Central Texas sees the highest concentrations because of the 8.6 million acres of Ashe juniper in the Hill Country.
Q6. Does cedar fever go away on its own?
Ans: Symptoms resolve when pollen levels drop, typically by late February or March. But the underlying sensitivity doesn’t go away , most people experience cedar fever annually unless they pursue immunotherapy or move out of the affected region.
Q7. What’s the best medicine for cedar fever?
Ans: A combination of a daily non-drowsy antihistamine (like cetirizine or loratadine) and a nasal corticosteroid spray (like fluticasone) is the most effective OTC approach. Start both before the peak season for best results. For long-term relief, immunotherapy (allergy shots or sublingual drops) is the gold standard.