El Nino Is Here. Here Is What Colorado's 2026 Weather Year Means for Pest Pressure in Mountain Communities

NOAA confirmed El Nino conditions in the Pacific this spring, and Colorado is simultaneously coming off one of the driest, warmest winters in recorded state history. For homeowners in Teller, Park, Chaffee, and El Paso Counties, that combination has a direct and practical consequence: pest activity in 2026 is running earlier and, in some cases, more intensely than the seasonal norms mountain residents are used to. This post explains what the climate data actually means -- and what to watch for on your property right now.

What this post covers:

• -What El Nino is and what it tends to mean for Colorado -- honestly, including the uncertainty

• -Why Colorado's 2026 drought year matters more than El Nino for near-term pest pressure

• -How dry, warm conditions accelerate wasp colony growth and increase rodent activity near homes

• -Why mountain communities like Woodland Park, Buena Vista, and Salida are seeing pest activity earlier than normal

• -What the forecast monsoon season may change later in summer -- and what it probably will not fix

• -Practical steps to take on your property now

What Is El Nino, and What Does It Actually Mean for Colorado?

El Nino is a climate pattern driven by warmer-than-normal water temperatures in the central and eastern Pacific Ocean. It influences weather patterns globally, but its effects on Colorado are less direct and less predictable than headlines often suggest.

NOAA issued an official El Nino Advisory in June 2026, confirming El Nino conditions are present and expected to strengthen into winter 2026-27. Historically, El Nino years have tended to bring wetter-than-average conditions to southern Colorado, most notably in fall and spring. For the current cycle, that would mean fall 2026 and spring 2027.

However, climate scientists at CU Boulder have noted that El Nino does not affect Colorado the same way it does other parts of the country, and it is genuinely unclear how much drought relief the state will see. The more immediate story for Colorado homeowners this summer is not what El Nino might eventually bring -- it is what the past several months of record drought have already set in motion.

Why Colorado's 2026 Drought Year Is the Bigger Driver of Pest Pressure

Colorado entered the 2025-26 winter in drought and exited it in historic drought. The Colorado Climate Center at CSU reported that statewide snowpack ended the winter at roughly 38% of the long-term median, with the majority of active monitoring stations recording their lowest snowpack values on record. By mid-spring, roughly 95% of the state was experiencing some level of drought, with large portions classified in the Extreme or Exceptional categories. The Governor's Office activated the State Drought Task Force.

That context matters for pest activity because drought and warm temperatures are precisely the conditions that favor certain pest populations. The relationship is not incidental -- it is biological. And it is playing out in the four-county area right now.

As a related data point: the Colorado State Forest Service documented a 148% increase in mountain pine beetle presence between 2024 and 2025, attributed to the same warm, dry winter conditions. Pine beetles are a forest pest, not a home pest, but that figure illustrates the broader dynamic -- prolonged drought stress accelerates pest pressure across species.

How Does Drought Affect Wasp Activity in Colorado?

Drought conditions favor wasp colonies in two specific ways: nest survival and colony size.

In a normal wet spring, a meaningful percentage of ground-level and low-structure wasp nests are damaged or destroyed by rain. Flooding collapses ground nests. Sustained moisture promotes fungal growth that can degrade nest material and harm developing larvae. In a dry spring like 2026, those checks largely disappear. Nests that would have failed in a wet year survive and grow.

Warm temperatures compound this. Wasp queens emerge from overwintering sites when temperatures consistently warm. A warm, early spring accelerates that emergence and gives colonies more time to build population before summer. By mid-June 2026, Teller County had already recorded multi-day stretches with highs in the 80s and lower 90s -- well above the mountain norm -- with a Red Flag Warning driven by relative humidity dropping into the single digits.

In our experience treating homes across Teller and Park Counties, residents typically start noticing wasp nest activity in late July or August at elevation. This year, we are seeing and hearing about activity that is running three to four weeks ahead of that window. That is consistent with what the conditions would predict.

Drought also changes wasp behavior in ways homeowners notice directly. When natural water sources dry up, wasps actively seek moisture near structures -- pet water bowls, drip irrigation, garden hoses, outdoor spigots. That brings them into closer and more frequent contact with people, even when no nest is nearby.

What About Rodents? Does Drought Increase Mouse and Rat Pressure Near Homes?

Yes, and this is one of the less-discussed consequences of drought years in Colorado mountain communities.

Deer mice and other rodents that inhabit the foothills and mountain zones surrounding Teller, Park, and Chaffee Counties are under resource stress during extended drought. Natural food sources -- seeds, grasses, plant material -- are reduced. Water is harder to find. That pressure causes rodents to range more widely and to investigate structures more aggressively in search of food, water, and shelter.

In Teller County specifically, deer mice are the primary small rodent species entering homes and outbuildings. Deer mice are also the primary carrier of hantavirus in Colorado -- a serious respiratory illness transmitted through contact with rodent droppings, urine, or nesting material. The CDC and Colorado Department of Public Health both note that hantavirus risk is elevated in cabins and outbuildings that have been closed for a season, particularly in rural Colorado counties. Drought years that push deer mouse populations toward structures are years to be more attentive about this risk, not less.

If you are opening a cabin, outbuilding, or storage area that has been closed since last fall, do not sweep or vacuum rodent droppings dry. Ventilate the space first, dampen any droppings with a diluted bleach solution, and use gloves. The CDC guidance on hantavirus prevention is worth reading if you spend time in rural Colorado properties.

Will El Nino's Monsoon Season Change the Picture Later This Summer?

Possibly -- but not as much as homeowners might hope, and not in the ways that matter most for pest pressure.

Forecasters are tracking a strong probability of an active North American monsoon season in July and August 2026, driven in part by the El Nino transition. The monsoon brings consistent afternoon thunderstorms to southern Colorado, including the Pikes Peak region and parts of the San Luis Valley. If that materializes, it could bring meaningful moisture to El Paso, Teller, and Chaffee Counties during the peak of summer.

For pest pressure, that has mixed implications. A wet July can interrupt late-season wasp colony growth to some degree -- rain damages exposed nests, floods ground sites, and reduces some of the foraging pressure that makes August yellow jackets so aggressive. Rodent pressure near structures may ease somewhat if natural food and water sources recover.

However, what the monsoon will not do is undo a pest season that started weeks early. Wasp colonies that have been building since April and May will be large by July regardless of what the weather does then. The 2026 pest season, as far as mountain Colorado homeowners are concerned, is already underway. The question now is whether you are positioned to address what is already on your property -- not waiting for rain to solve it.

What Should Teller, Park, and El Paso County Homeowners Do Right Now?

Inspect eaves, soffits, and overhangs now, not in August.

Paper wasp nests and early yellow jacket colonies are far easier and safer to address in June than in late summer when populations peak. A nest found now is a manageable situation. The same nest found in August, when colony size may be ten times larger, is a different conversation.

Look for yellow jacket entry points at ground level and in siding.

Yellow jackets entering a gap in siding, a foundation crack, or a hole in the ground are accessing a void that will only grow more populated as summer progresses. Entry point location now matters for treatment planning.

Audit your property for rodent entry points before fall.

Drought years tend to produce elevated fall rodent pressure as temperatures drop and rodents that have been ranging widely begin seeking winter shelter. Sealing gaps in the foundation, installing hardware cloth over crawlspace vents, and addressing known entry points now is more effective than responding after entry has occurred.

If you have a cabin or outbuilding that has been closed since fall, inspect it carefully.

Deer mouse activity in enclosed structures is a real consideration in Teller and Park Counties in any year. In a drought year with rodent populations under resource stress, it is worth a deliberate inspection before the property sees heavy use.

John Chaney conducts hands-on property inspections across the four-county service area and can assess both what is present and what structural conditions are creating as attractants. Chaney Pest Elimination is licensed under the Colorado Department of Agriculture.

Frequently Asked Questions

Does El Nino mean more bugs in Colorado?

Not directly. El Nino's effects on Colorado are less predictable than in other parts of the country, and the connection between El Nino and pest pressure is indirect. What matters more for Colorado in 2026 is the record drought that preceded the El Nino transition -- warm, dry conditions that reduce nest mortality, accelerate colony growth, and stress rodent populations into seeking food and shelter near homes.

Why are there so many wasps in Colorado this summer?

Colorado's 2025-26 winter and spring were historically warm and dry. Those conditions allowed wasp colonies to start earlier and survive at higher rates than in wet years. Without spring rains to flood ground nests or damage structure-attached nests, more colonies survived to build population through June. The result is a wasp season that appears to be running three to four weeks ahead of normal in mountain communities at elevation.

Is rodent pressure higher in drought years in Colorado?

Yes. Drought reduces the natural food and water sources that rodents -- particularly deer mice in mountain Colorado -- depend on. That pressure causes them to range more widely and investigate structures more aggressively. Teller, Park, and Chaffee County homeowners should expect elevated rodent activity near homes and outbuildings in fall 2026, and should prioritize exclusion work before temperatures drop.

Will the monsoon season reduce pest pressure this summer?

An active monsoon in July and August may interrupt some late-season wasp colony development and ease rodent resource stress if natural food sources recover. However, it will not reverse a pest season that started early. Colonies that built through a warm, dry spring will be large regardless of summer rain. Addressing pest pressure now rather than waiting for weather to resolve it is the more reliable approach.

When should I call a pest control professional versus handling a wasp nest myself?

Small, accessible paper wasp nests found early in the season are generally manageable with a consumer aerosol applied at night. Yellow jacket nests inside wall voids, ground nests near the home's perimeter, large bald-faced hornet nests, and any nest in a high-traffic area warrant professional treatment. If there is a known venom allergy in the household, do not attempt DIY treatment regardless of nest size.

Seeing unusual pest activity on your property this season? Chaney Pest Elimination serves Teller, Park, Chaffee, and El Paso Counties. Call 719-650-0246 to schedule an inspection with John Chaney.