Spring brings beautiful flowers and fragrant lilacs, but also tree pollen that coats cars and triggers sneezing, wheezing, and headaches. As an allergist and immunologist at the University of Colorado School of Medicine, I help patients with seasonal allergies manage their conditions. A common question is whether this season will be worse than last year. With a record warm start to spring 2026 in much of the US, the answer is a teary-eyed yes.
What Are Allergies?
More than 1 in 4 US adults suffer from seasonal allergies, a number expected to rise as climate change lengthens and intensifies pollen seasons. Allergic rhinitis or conjunctivitis—inflammation of the nose or eyes due to allergen exposure—causes itchy, watery eyes, runny nose, sneezing, congestion, and nasal itching. These symptoms occur when allergens are airborne during spring, summer, and fall.
The main driver is pollen proteins. Pollen is the male reproductive material plants release to spread their species. When the immune system develops allergic antibodies (IgE) to these proteins, binding triggers the release of histamine, prostaglandins, and leukotrienes, which interact with blood vessels and nerves to cause symptoms.
Which Pollens Cause Symptoms?
Pollen season begins with trees in late winter and early spring. Mountain cedars in Texas release pollen from November through January, causing cedar fever. Grasses emerge later, causing symptoms from April to July. Ragweed and other weeds release pollen until a freeze stops production.
What Makes a Season Worse?
Key factors include the length of the growing season and pollen amount, both expanding due to climate change. Rising global temperatures have lengthened growing seasons. In 2026, unprecedented warmth drove early tree pollen emergence. Growing seasons are now two weeks longer than in the 1990s and over four weeks longer than in the 1970s. Increased atmospheric carbon dioxide boosts plant growth, leading to longer pollination and more pollen. Higher pollen counts cause more people to develop symptoms, including first-time sufferers. Windy days spread pollen, while rain temporarily clears it but can cause pollen granules to rupture, making them easier to inhale, especially grass pollen.
How to Avoid Symptoms
Manage allergies by reducing exposure. Keep windows closed during pollen season. Wipe pets with a damp towel to remove allergens. Avoid clotheslines to keep pollen off washed items. Change clothes or shower after being outdoors. Use HEPA air purification (non-ionizing to avoid ozone). Check the National Allergy Bureau pollen forecast; counts are highest in the morning, but pollutants like PM2.5 and ozone peak in midday and afternoon heat.
Do Medications Work?
Saline nasal rinses reduce mucus and allergens. For mild symptoms, daily nonsedating antihistamines are effective. Moderate to severe allergies may require daily nasal steroids, which take weeks to peak. Nasal antihistamine sprays offer added benefits. Antihistamine eye drops help. In dry climates like Colorado, nasal hydration with saline sprays eases congestion. If medications fail, consider immunotherapy (allergy shots), which require weekly or monthly shots over years. They reduce symptoms but have side effects like local reactions and rare anaphylaxis.
Allergies are miserable but manageable, even in an overproductive year like 2026. Understanding causes and finding the right solutions helps you enjoy spring flowers and sunshine.
