Mosquito season might last longer in SC this year, DPH says. Here’s why, how much longer

Have you already felt the wrath of mosquitoes this year, just as you started enjoying outdoor weather?

You’re not alone. Mosquito season is usually supposed to start late spring through early fall, when temperatures consistently stay above 50 degrees, while peak activity is during July and August.

However, mosquito season this year is expected to start earlier and last longer than previous years, according to the South Carolina Department of Public Health, in an email conversation with The State.

Dr. Chris Evans, a DPH State Public Health Entomologist, answered questions regarding this year’s mosquito season.

Here’s what he said:

How long will SC mosquito season last?

According to Evans, warmer temperatures in SC have made mosquito season longer by extending mosquito activity from October into November.

“Earlier-than-normal warm temperatures can increase disease transmission by speeding up mosquito breeding and virus replication,” he said.

Last week, SC experienced extremely warm temperatures for this early in the year, with some parts of the state reaching up to 87 degrees. This week is looking especially hot, too, for Columbia.

The National Weather Service predicted warmer temperatures this spring in their Seasonal Temperature Outlook, and the forecast seems to be accurate, so far. If the warmer weather trend continues, peak mosquito activity might also last longer.

How intense will mosquito activity be this year?

While it’s very likely mosquito season will be more troublesome this year, it’s impossible to say for sure what the numbers will look like until we’re further into the season.

“No one can say with certainty exactly how intense mosquito season will be in South Carolina in 2026. Weather varies year to year, and mosquito populations respond to very local conditions like rainfall, temperature swings, and standing water,” Evans said.

The most common diseases from mosquitoes

Mosquitoes are mostly just an annoying part of SC’s climate, but they can also cause very serious health issues, like spreading diseases.

The DPH has a dedicated website for mosquitos in SC, with information about the winged insect here.

According to the DPH, the most common diseases that could potentially be carried by mosquitoes in South Carolina include:

• West Nile 
• Eastern Equine encephalitis
• La Crosse encephalitis
• Saint Louis encephalitis virus
• Dog/cat heartworm

The DPH recently released a Mosquito-Bourne Disease Dashboard to track the number of mosquito-disease related cases in the state. There are currently zero cases of mosquito-borne diseases this year, but there were 20 total cases from Dengue, West Nile and Malaria in 2025.

Tips to prevent mosquito bites

Staying inside is obviously the easiest way to avoid getting bit by mosquitoes, but some people can’t avoid going outside.

The next possible way to avoid mosquito bites is by using skin products. The EPA said to look for the following active ingredients in mosquito repellent that provide reasonably long-lasting protection:

• DEET (this should not be used on infants less than two months old)
• Picaridin
• Oil of Lemon Eucalyptus (this should not be used on children less than three years old)

Wearing clothes made with tightly woven fabrics and that cover as much skin as possible is ideal. Wearing light-colored clothing is also an easy way to stay protected against mosquitoes, because they make you less visible to the insects’ heat-seeking, low-light vision.

This story was originally published March 10, 2026 at 6:00 AM.