Mosquito Intelligence Index

The Mosquito Intelligence Index at the top of this page shows the current score updated every 5 minutes from live weather data. A score below 16 means little to no activity. Above 46 means repellent is a good idea. The score, activity level label, and plain-language description all update together so you always have a clear answer without needing to interpret raw numbers.

A 0-to-100 score that estimates real-time mosquito flight activity in Hardeeville, SC. It combines live temperature, humidity, wind speed, and rain probability from OpenWeatherMap, then applies a time-of-day multiplier and a seasonal population multiplier calibrated for Jasper County's Lowcountry mosquito species. It is not a trap count -- it is a behavioral model that tells you how favorable conditions are for mosquito flight right now.

March through November -- roughly 9 months. Hard freezes that would collapse mosquito populations are rare in Hardeeville, so populations never fully die off between seasons. South Carolina's mosquito season has grown about 11 days longer on average compared to 40 years ago, and the Lowcountry leads that trend. Peak pressure runs June through September, with the worst biting at dusk and dawn during those months.

Peak activity hits at dusk (6-9 PM) and again at dawn (5-7 AM). Most Lowcountry species -- Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus -- are crepuscular, meaning they are most active in low-light conditions. Midday activity drops sharply as mosquitoes seek shade and shelter from heat and UV radiation. Check the Next Hours forecast at the top of this page to see how conditions are trending toward those peak windows today.

Yes. West Nile virus is endemic in South Carolina and cases are reported annually. The primary vector is Culex quinquefasciatus, the southern house mosquito, which is common throughout Jasper County year-round. Eastern Equine Encephalitis (EEE) is also present in the region. Most West Nile infections cause no symptoms, but about 1 in 5 people develop fever and flu-like illness, and about 1 in 150 develop serious neurological disease.

The SC Department of Public Health monitors local mosquito populations through the ArboNET surveillance program and publishes a live Mosquito-Borne Disease Dashboard. DEET-based repellents and eliminating standing water are your most effective personal defenses.

Significantly. Mosquitoes are weak fliers and cannot navigate effectively in sustained wind. At 10 mph the index applies a 40% reduction to the score. At 15 mph or above, the reduction is 55%. A steady Lowcountry afternoon sea breeze is one of the most reliable natural suppressors of mosquito activity available -- which is why evening wind speed is one of the four live inputs displayed on this page.

Active rainfall grounds mosquitoes -- raindrops are large relative to their body mass and can knock them out of flight. When rain probability is 60% or higher, the index caps the score at 36 (Light or below). But rain has a second effect: the standing water it leaves behind becomes prime breeding habitat. Expect elevated activity 7-14 days after a significant storm as newly hatched adults emerge. The index will capture that surge automatically through its temperature and humidity inputs.

Mosquitoes lose water rapidly through their cuticle (exoskeleton) in dry air, which limits how long they can stay active. High humidity -- above 70% -- reduces that desiccation stress and lets them fly farther from resting sites and stay active for longer periods. Hardeeville's average relative humidity runs 75-85% through the active season, meaning high-humidity conditions are the norm here rather than the exception. The index adds up to 8 points to the score at 80%+ humidity.

For the Lowcountry's aggressive species during peak season, DEET (20-30%) or Picaridin are most effective. IR3535 and Oil of Lemon Eucalyptus (OLE) are solid EPA-registered alternatives. For extended outdoor time during High or Extreme conditions, Permethrin-treated clothing adds a second layer of protection -- apply it to gear, not skin. Reapply any repellent per label directions, especially after sweating or swimming.

Repellent recommendations on this page follow EPA-registered active ingredient guidance.

The tidal marshes and river backwaters stretching west from I-95 toward the Savannah River provide continuous shallow-water breeding habitat. Saltmarsh mosquitoes (Ochlerotatus taeniorhynchus) are aggressive biters capable of traveling several miles from their breeding sites, meaning residents well inland can be affected. Freshwater wetlands add a second layer of pressure from Aedes and Culex species that thrive after rainfall floods low areas. The Mosquito Habitat Map on this page shows every federally mapped wetland near Hardeeville so you can see exactly which areas carry the highest breeding pressure.

Source reduction -- eliminating standing water -- is the single most effective personal control measure. Empty or flush gutters, birdbaths, pot saucers, tarps, and any container that holds water after rain. Retention ponds and drainage swales throughout Hardeeville's newer developments are major local sources that are harder to address individually. For professional treatment, Jasper County residents can contact the county about mosquito abatement programs. The SC DHEC Mosquito-Borne Disease Dashboard tracks active surveillance and control efforts statewide.

The Mosquito Intelligence Index is a composite environmental-behavioral model, not a trap count or direct population measurement. It estimates the probability and intensity of mosquito flight activity in Hardeeville at any given moment. Every calculation uses live data from OpenWeatherMap pulled at the coordinates 32.2871°N, 81.0807°W, refreshed every five minutes. The model runs six sequential steps.

Step 1 — Temperature base score. Temperature is the primary input. Mosquitoes are ectotherms -- their metabolic rate, wing-beat frequency, and host-seeking behavior are all directly tied to ambient air temperature. Below 45°F (7°C), enzymatic activity in flight muscle falls below the threshold for sustained wing movement and the score is 0. As temperature rises, the base score increases non-linearly through fixed thresholds: 8 at 45–51°F (near-dormant, overwintering adults may survive but not actively fly); 18 at 52–59°F (marginal activity, cold-tolerant Culex adults may be present); 28 at 60–64°F (limited flight, early-season Aedes possible); 38 at 65–69°F (active, host-seeking begins in earnest); 52 at 70–74°F (favorable, oviposition and blood-feeding both increase); 64 at 75–79°F (high, most Lowcountry species near peak metabolic rate); 76 at 80–84°F (very high, Culex quinquefasciatus gonotrophic cycle shortens to 48–72 hours); 86 at 85–89°F (near-extreme, heat stress begins suppressing midday activity but dawn and dusk intensity is high); and 94 at 90°F and above (extreme baseline, larval development completes in as little as 4–5 days).

Step 2 — Humidity adjustment. Mosquitoes have a large surface-area-to-volume ratio and lose water rapidly through their cuticle via transcuticular evaporation. In dry air, they desiccate and are forced to shelter or reduce activity. This adjustment is added to the Step 1 base score: +8 points at relative humidity 80% or above; +4 points at 70–79%; +1 point at 60–69%; no change at 45–59%; minus 6 points below 45%. Hardeeville's coastal proximity and tidal marsh environment produce average relative humidity of 75–85% throughout the active season, meaning the full +8 adjustment is the typical case, not the exception.

Step 3 — Rain suppression. Falling rain creates direct mechanical hazard for a flying insect that weighs approximately 2–2.5 milligrams. A single raindrop can carry 50–100 times the mass of a mosquito. At precipitation probability 60% or higher, the score is hard-capped at 36 (the top of the "Light" level), regardless of temperature or humidity. At 40–59% probability, the score is multiplied by 0.85, a 15% reduction reflecting partial suppression. Below 40%, no rain adjustment is applied. Note: rain suppresses flight now but creates breeding habitat. Standing water pools that persist for 7 or more days at temperatures above 60°F will produce new adult mosquitoes; the index will capture that surge through its temperature and humidity inputs when it arrives.

Step 4 — Wind suppression. Mosquitoes generate approximately 0.1–0.3 millinewtons of thrust. Sustained wind above 7 mph begins to exceed their flight correction capability. The adjustment is applied as a multiplier: 0.45 (55% reduction) at 15 mph and above; 0.60 (40% reduction) at 10–14 mph; 0.80 (20% reduction) at 7–9 mph; no adjustment below 7 mph. This produces the raw environmental score -- what ambient conditions alone suggest about mosquito flight potential -- capped at 100 and floored at 0.

Step 5 — Time-of-day multiplier. The dominant Lowcountry species are crepuscular: Aedes albopictus (Asian tiger mosquito) is most active in the 2–3 hours after dawn and before dusk; Aedes aegypti shows similar crepuscular peaks; Culex quinquefasciatus (southern house mosquito) is primarily nocturnal with its strongest host-seeking activity between dusk and midnight. The multiplier values applied by hour are: 6–9 PM (1.00, primary dusk peak); 6–8 AM (0.90, dawn peak, strong for Culex); 4–6 AM (0.75, pre-dawn, activity building); 9–11 PM (0.70, post-dusk tapering); 4–6 PM (0.65, pre-dusk buildup); 8–10 AM (0.55, transitioning from dawn activity); 11 PM–midnight (0.55, still elevated as Culex remain active); midnight–4 AM (0.45, reduced overnight, most species resting); 10 AM–4 PM (0.30, midday minimum, UV radiation and heat drive most species to shelter).

Step 6 — Seasonal population multiplier. Identical environmental conditions produce very different biting pressure in May versus August because the standing adult population -- and the rate of new adult emergence from breeding sites -- is much larger in peak season. The multiplier values by month are: January 0.15, February 0.15, March 0.30, April 0.50, May 0.65, June 0.85, July 1.00, August 1.00, September 0.90, October 0.70, November 0.40, December 0.20. These values are calibrated for Jasper County's humid subtropical climate and the 9-month active season typical of coastal South Carolina.

Final calculation. Final score = (Step 1–4 environmental score) × (Step 5 time multiplier) × (Step 6 seasonal multiplier), rounded to the nearest integer, capped 0–100. The result maps to ten named activity levels: None (0–7), Dormant (8–15), Minimal (16–25), Light (26–35), Low (36–45), Moderate (46–57), Active (58–67), Elevated (68–77), High (78–87), and Extreme (88–100). Each level carries a specific protection recommendation shown in the Protection Guide on this page.

Limitations. The model estimates flight behavior, not trap-count abundance. Population density varies by neighborhood based on proximity to wetlands, standing water management, and local control activity. Saltmarsh mosquitoes (Ochlerotatus taeniorhynchus) can produce localized post-tidal surge events not fully captured by the weather-driven inputs. The seasonal multiplier approximates a smooth seasonal curve; actual population cycles are pulsed by rainfall events and temperature spikes. For official mosquito surveillance data, consult the SC DHEC Mosquito-Borne Disease Dashboard.