This year has seen an alarming increase in spider sightings across Colorado, leading many residents to ask, “why are there so many spiders this year?” This surge has been particularly noticeable in cities such as Denver, Boulder, Colorado Springs, and Fort Collins, as well as smaller towns like Longmont, Loveland, and Fort Morgan. Several factors contribute to this phenomenon, ranging from unusual weather patterns to changes in habitat and food availability. This article explores these factors in detail, explaining why spiders are so bad this year and why there are more spiders in Colorado in 2024.

One of the most significant reasons behind the spike in spider activity this year is the unusual weather conditions. Denver, for instance, experienced the wettest April of the 21st century, and February was the third wettest February in Denver’s weather history. These conditions create an ideal environment for spider proliferation for several reasons:

Spiders thrive in moist environments. The excessive rainfall this year increased the humidity levels and created more moist habitats, which are perfect for spiders to live and breed. Moisture-rich environments support the growth of insects, which are the primary food source for spiders. This abundance of food allows spider populations to flourish.

Changes in the environment due to construction and landscaping have also played a role in increasing spider sightings. New construction projects and landscaping disrupt the natural habitats of spiders, causing them to seek shelter indoors. Homeowners in rapidly growing cities like Denver and Boulder are particularly affected as urban development continues to encroach on natural habitats.

Another critical factor is the increase in insect populations. The wet weather has led to a boom in the populations of various insects, which are prey for spiders. Insects such as flies, mosquitoes, and ants have become more prevalent, providing an abundant food source for spiders. This increase in food availability supports larger spider populations, which in turn leads to more spider sightings.

The wetter-than-usual weather has created ideal conditions for many insects to thrive. Mosquitoes, for example, lay their eggs in stagnant water, and the increased rainfall has resulted in more breeding sites. Similarly, flies and other flying insects find moisture-rich environments perfect for their reproduction cycles. As these insects multiply, they become an abundant food source for spiders.

The wet conditions have also affected the nesting habits of ground-dwelling insects like ants and beetles. Ants, in particular, often seek higher ground to escape waterlogged nests, making them more likely to enter homes. Once inside, they attract spiders that follow their prey into human habitations. Additionally, the damp soil conditions have supported the growth of plants and organic matter, which in turn supports a healthy population of plant-eating insects. This cascade of environmental effects leads to a plentiful and consistent food supply for spiders.

• Flies: With increased moisture and organic matter, fly populations have surged. Flies are a common prey item for many spider species, which set up webs in areas with high fly activity.
• Mosquitoes: Standing water from heavy rains creates perfect breeding grounds for mosquitoes. As mosquito populations rise, spiders that specialize in catching these insects also increase.
• Ants: Rain can drive ants indoors, and where ants go, spiders often follow. Ants are not just a food source but also attract other insects, further contributing to a rich hunting ground for spiders.
• Beetles: Moist conditions support the proliferation of beetles, another significant food source for spiders. The increased plant growth from the wet weather also supports beetle larvae, ensuring a steady food supply for spiders.

The daily rainfall in Denver for 2024. Provided by WeatherSpark.com

Spiders exhibit seasonal behavior, with activity peaking during certain times of the year. Typically, spider activity increases during late summer and early fall, which coincides with their mating season. Male spiders become more mobile in search of females, leading to higher visibility. This seasonal surge can be exacerbated by favorable environmental conditions, making the spider problem in Colorado even more pronounced this year.

As the weather cools, spiders tend to move indoors seeking warmth and stable environments. This indoor migration is particularly noticeable during the transition from summer to fall. Homeowners in Colorado cities often report an increase in indoor spider sightings as spiders seek refuge from the cooling temperatures outside.

Denver has seen a significant increase in spider activity this year, partly due to the record-breaking wet weather. The city’s extensive green spaces and urban gardens have become ideal habitats for spiders and their prey. Residents are advised to seal entry points and reduce clutter to minimize indoor spider sightings.

Boulder’s proximity to the mountains and its high rainfall this year have contributed to the increase in spider populations. The city’s natural landscape provides numerous hiding spots for spiders, making them more visible to residents. Regular outdoor maintenance and insect control can help manage the spider population in this area.

Colorado Springs has experienced similar issues, with spiders becoming more common in homes and gardens. The city’s varied climate and frequent precipitation have supported the growth of insect populations, thereby attracting more spiders. Homeowners should focus on pest control measures to keep both insects and spiders at bay.

Fort Collins, known for its lush parks and agricultural areas, has also seen a rise in spider sightings. The wet weather has created a conducive environment for spiders and their prey, leading to increased activity. Outdoor maintenance and proper waste management are crucial in managing spider populations in Fort Collins.

In Evergreen, the combination of natural landscapes and the year’s wet weather has led to a noticeable increase in spider activity. The dense vegetation and cooler temperatures make it an ideal habitat for spiders and their prey. Regular yard maintenance and sealing entry points can help keep spiders at bay.

In Longmont and Loveland, residents are also experiencing higher than usual spider sightings. The mix of suburban homes and nearby farmlands creates a unique environment where spiders thrive. Ensuring that homes are well-sealed and that yards are kept tidy can help reduce spider encounters.

In Fort Morgan, the agricultural landscape and this year’s wet weather have contributed to an increase in spider populations. Spiders find ample food sources and nesting sites in these environments, leading to more frequent indoor sightings as they seek warmth and stability.

If you find yourself overwhelmed by the number of spiders in your home, it might be time to seek professional help. OBEX offers comprehensive pest control services to help manage and reduce spider populations in your home. Their expert technicians can assess your situation and provide targeted solutions to significantly reduce spider populations.

The combination of unusual weather patterns, habitat disruption, increased food sources, and seasonal behavior has led to a noticeable increase in spider sightings across Colorado. Cities like Denver, Boulder, Colorado Springs, Fort Collins, Evergreen, Longmont, Loveland, and Fort Morgan are all experiencing higher than usual spider activity. For more detailed weather information affecting spider populations in Colorado, visit WeatherSpark. Understanding these contributing factors helps residents manage their environments better and address the influx of spiders more effectively.

¹ During regular business hours (Monday – Friday, from 9 am to 5 pm), an OBEX representative and/or sales agent will contact you via call, text, email, and/or combination of the like, for the sale of pest control services. You agree that standard text messages and/or data rates may apply, and promotional/sale messaging can be stopped at any time by replying STOP, or unsubscribing at the bottom of emails. Claim of a reply “within minutes” is average response time during operation hours, and is not guaranteed. 

Four+℠, Six+℠ and Six Pro℠: Twelve-month (12) agreement required. Early cancel fee may apply. All OBEX 365℠ plans: Spot treatment re-services requests may require waiting period, due to local, state and/or federal regulatory laws of pesticide applications or other routing conflicts. At its sole discretion, OBEX may limit the amount of free applications a customer may receive, and does not guarantee a specific timeframe requested by the customer may be available. Active pest issue must be occurring at the time of request, and visit requires someone over 18 to be present for the entire treatment.

* Service does not include the control or prevention of wood infesting organisms such as termites, powder post beetles, wood borers, carpenter ants, carpenter bees, wood wasps, or wood decay fungus. OBEX will treat for wasp nests on homes; however, we do not guarantee for flying insects. See Pest Control Service Agreement for additional information and limitations.