Mosquito season in full swing as warm temperatures persist in Las Vegas

Mosquito season has come early to the Las Vegas Valley this year.

With record-high temperatures in March that created an optimal environment for the bloodsucking insects to breed, the timeline of mosquito season — traditionally lasting between late April and late October — has been effectively extended by a month, according to Louisa Messenger, an assistant professor at UNLV’s School of Public Health.

If Southern Nevada sees similar weather conditions persist into the summer, the valley’s mosquito population could “explode,” Messenger warned.

“We already have a decent density of mosquitoes in the environment here in Southern Nevada,” she said. “Obviously we are still very early in the season, but the density is concerning.”

In response to unseasonably high temperatures, environmental health workers with the Southern Nevada Health District began setting mosquito traps in early March this year to monitor the valley’s booming mosquito populations and detect mosquito-borne viruses.

Of the 7,785 mosquitoes the health district has submitted for testing thus far, none have tested positive for diseases such as West Nile virus, health district data shows. But traps are currently capturing mosquitoes at a high rate that is more often seen in the mid-summer months of June and July, according to Christian De Haan, a senior environmental health specialist with the health district.

“We’re definitely off to a running start with the heat in March,” De Haan said. “The heat and those rains (in February) really did contribute to a larger number of mosquitoes than we usually find at this time of year.”

Messenger said traps set by her Parasitology & Vector Biology Lab at UNLV have also collected more-than-usual amounts of mosquitoes for this time of year.

‘This is just the beginning’

News of an extended mosquito season was not a surprise to Johnny Longhurst, the operations manager at JS Pest Control.

Longhurst said his company began offering mosquito control services about three years ago to meet the growing demand in the Las Vegas Valley but saw a new trend this winter.

Even after mosquito season ended, Longhurst said, his company kept getting calls from customers requesting mosquito control services. Longhurst estimated his office received six calls per day for mosquito control through the winter, a phenomenon he attributed to moderate winter temperatures.

“We never had calls in March or February for mosquitoes, but this year we did. We even had some calls in January,” said Longhurst, who has done pest control in the valley for 38 years. “I don’t see them dying off in the winter anymore. Maybe if we had a winter where there were several freezes, but this year we didn’t have that.”

Last year’s mosquito season was relatively tame, with no reported human cases of West Nile virus in Clark County. In 2024, high levels of mosquito activity early into the season ended with 14 neuroinvasive cases and 12 non-neuroinvasive cases of West Nile virus recorded in the county.

De Haan said it’s difficult to predict how exactly the valley’s mosquito population may manifest this year, as weather plays a big factor. But for now, he said, “there’s no need to panic.”

“With the increased number of mosquitoes, it means there’s more of them out there that might be biting you,” De Haan said. “If you react poorly to mosquito bites, it’s important to take precautions to protect yourself.”

For valley residents struggling to escape the bites, Messenger and De Haan both recommended wearing long-sleeved clothing to protect the skin and applying EPA-approved topical insect repellents regularly. Both experts added that removing standing water on one’s property can help reduce mosquitoes by giving them fewer places to breed.

De Haan said Southern Nevada residents with mosquito activity at their home can receive overnight mosquito traps by calling the health district at 702-759-1633.

“This is just the beginning,” De Haan said. “We don’t know what we’re going to see, but it’s important right now to start taking precautions. If later in the season we start to find disease, then it will be even more important to start taking precautions.”