Mosquitoes in the Lowcountry arrive in waves. A flood tide or a soaking rain hatches eggs in the marsh and in your yard, and about a week later the bites start. Enter your ZIP code to see the next 7 days, and whether a recent hatch is headed your way.
Type your 5-digit ZIP code and press the green button. Your free 7-day forecast appears right below.
Tall dark bars flooded the marsh. The green zone is when those eggs turn into biting mosquitoes.
Charleston sits on tidal marsh. The black salt marsh mosquito lays its eggs on damp marsh mud above the usual waterline, and they wait there until a high tide or heavy rain floods them.
In 2025 the tide at Charleston Harbor reached NOAA's 7-foot minor flood stage on 43 different days, each one a chance to flood marsh eggs.
Our count of NOAA station 8665530 recordsUnder ideal conditions, adult salt marsh mosquitoes can emerge as little as six days after the eggs hatch.
Rutgers Center for Vector BiologyHow far female salt marsh mosquitoes generally fly, so a hatch on the marsh can reach yards well inland.
Rutgers Center for Vector BiologyThree public data feeds, checked against published mosquito biology. Every rule the forecast uses is listed here, so you can see exactly why it says what it says.
Salt marsh mosquito eggs are laid in moist soil, not in water, and hatching depends on flooding by rainfall or tides, according to the University of Florida IFAS. We read observed and predicted high tides from NOAA's Charleston Harbor gauge.
Rain floods low ground and fills buckets, saucers and gutters. Container mosquitoes take about 7 days to go from egg to adult, per the LSU AgCenter. Past rain comes from NOAA's Charleston International Airport records; future rain from the National Weather Service.
Climate Central defines a "mosquito day" as one with average relative humidity of 42% or higher and daily low and high temperatures between 50°F and 95°F (Climate Central, May 2023). We apply it to the Weather Service forecast for your ZIP code.
Timing: larvae take 5 to 15 days to develop depending on temperature, and pupae a couple of days more (UF/IFAS). So the forecast expects adults 6 to 17 days after each trigger.
Answers drawn from university extension research and public NOAA data.
Black salt marsh mosquitoes lay their eggs on damp marsh soil above the normal waterline. When an unusually high tide or heavy rain floods that ground, the eggs hatch, and larvae develop in 5 to 15 days depending on temperature (UF/IFAS). Rutgers reports adults can emerge in as little as six days. That lag is why the bites arrive after the flooding, not during it.
Females generally fly 2 to 5 miles, and wind-assisted flights of more than 30 miles are known, according to the Rutgers Center for Vector Biology. A yard that is nowhere near the water can still feel a marsh hatch.
At least once a week. Mosquitoes take about 7 days to go from egg to adult, so emptying containers weekly breaks the cycle (LSU AgCenter). After a soaking rain, check plant saucers, buckets, toys, tarps, birdbaths and clogged gutters within a few days.
Mosquitoes need warmth and humidity, and the Southeast gets a lot of both. Climate Central found that the Southeast and South have mosquito-friendly weather on more than half the days of the year. The forecast above uses Climate Central's mosquito-day test to answer the question for the week ahead in your ZIP code.
No. It is an estimate built by Vinx Pest Control from public NOAA and National Weather Service data, using the published rules listed above. Local conditions such as drainage and shade matter too. For county spraying schedules, see Charleston County Mosquito Control.
Tides come from NOAA's Charleston Harbor station (8665530). The 7-day weather forecast comes from the National Weather Service, which updates it several times a day. Past rainfall comes from NOAA's daily records for Charleston International Airport, which are published one to three days late. Everything is pulled fresh each time you run the forecast.
Yes. Newsrooms are welcome to cite the forecast or link to this page. For an interview with a licensed Vinx technician about mosquito activity in the Lowcountry, please contact us.
The forecast is built entirely on public government data and university extension research. It is an estimate, not medical or public-health advice.
Vinx mosquito service runs monthly from April through November, plus one winter visit, on our Platinum plan. See how it works in Charleston.