Methodology | Pressure Forecast

How It Works

Mosquito populations are highly dependent on weather conditions. Unlike calendar-based treatment schedules, our model predicts actual mosquito pressure by analyzing the environmental factors that drive mosquito development, breeding, and activity.

35 pts max

🌡️ Degree Day Accumulation

Heat accumulation above the development threshold tracks mosquito maturation from egg to biting adult. More degree days = faster development = more mosquitoes.

25 pts max

🌧️ Breeding Habitat

Rainfall 5-14 days ago creates standing water breeding sites. We model the lag between precipitation and adult emergence based on temperature.

25 pts max

💨 Activity Conditions

Current temperature, humidity, and wind speed determine whether adult mosquitoes are actively flying and biting.

15 pts max

📈 Population Lag

Recent high-pressure days contribute to current populations due to overlapping generations and adult longevity.

Scoring Formula

The Pressure Score is a composite index from 0-100 that combines all environmental factors, with penalties applied for conditions that suppress mosquito activity.

Pressure Score = DD_score + Habitat_score + Activity_score + Lag_score − Penalties

Where each component is capped at its maximum weight, and penalties reduce the score for unfavorable conditions (high wind, extreme temperatures).

Risk Level Thresholds

0-19 Low

20-39 Moderate

40-59 High

60-79 Very High

80-100 Severe

Degree Day Model

The degree-day (DD) model is the foundation of our forecasting approach. It's based on the principle that mosquito development is temperature-dependent: insects are ectothermic ("cold-blooded") and require accumulated heat units to complete their lifecycle.

Daily DD = max(0, (T_max + T_min) / 2 − Development Threshold)

If the average daily temperature is below the species' development threshold, no degree days accumulate. Each species has a characteristic number of degree days required to develop from egg to adult.

Development Parameters by Species

Different mosquito species have different thermal requirements. Our model uses species-specific parameters derived from peer-reviewed entomological research:

Species	Dev. Threshold	DD to Adult	Optimal Range	Primary Diseases
Aedes aegypti Yellow Fever Mosquito	52°F (11°C)	169 DD	72-90°F	Dengue, Zika, Chikungunya
Aedes albopictus Asian Tiger Mosquito	50°F (10°C)	180 DD	68-86°F	Dengue, Zika, EEE
Culex pipiens Northern House Mosquito	52°F (11°C)	246 DD	68-82°F	West Nile Virus
Culex quinquefasciatus Southern House Mosquito	52°F (11°C)	246 DD	72-88°F	West Nile Virus, SLE
Culex tarsalis Western Encephalitis Mosquito	50°F (10°C)	220 DD	70-85°F	West Nile, WEE, SLE

Regional Calibration

Mosquito species composition varies significantly by region. We calibrate the model to account for the dominant species in each area, which affects development thresholds, season timing, and activity patterns.

Region	Primary Species	Season	Rain Lag
Northeast	Cx. pipiens, Ae. albopictus	April - October	10 days
Southeast	Ae. aegypti, Ae. albopictus, Cx. quinquefasciatus	March - November	7 days
Midwest	Cx. pipiens, Ae. albopictus	April - October	10 days
Southwest	Ae. aegypti, Cx. tarsalis	March - November	8 days
West Coast	Cx. tarsalis, Cx. pipiens	April - October	9 days
Gulf Coast	Ae. aegypti, Cx. quinquefasciatus	February - December	6 days

Data Sources

Our forecasts rely on high-quality weather data and established entomological research:

🌤️

Open-Meteo Weather API

Real-time and forecast weather data including temperature, humidity, precipitation, and wind speed. Open-Meteo aggregates data from national weather services including NOAA, DWD, and others.

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Climate Normals (1991-2020)

30-year climate averages used for annual planning and seasonal predictions. Provides baseline expectations for temperature and precipitation patterns.

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ZIP Code Geocoding

Location lookup via Zippopotam.us for converting ZIP codes to coordinates and identifying the appropriate regional calibration profile.

Scientific References

Our model parameters are derived from peer-reviewed entomological research:

Grech, M.G., et al. (2015). "New records for Culex pipiens quinquefasciatus in Patagonia." Development threshold temperatures and degree-day requirements for Aedes aegypti (DTT=11.1°C, PT=93.7 DD) and Culex quinquefasciatus (DTT=10.96°C, PT=136.9 DD).

Shocket, M.S., et al. (2020). "Transmission of West Nile and five other temperate mosquito-borne viruses peaks at temperatures between 23-26°C." eLife 9:e58511. Thermal performance curves showing optimal transmission temperatures.

Mordecai, E.A., et al. (2019). "Thermal biology of mosquito-borne disease." Ecology Letters, 22: 1690-1708. Comprehensive review of temperature-dependent transmission dynamics.

Reisen, W.K. (1995). "Effect of temperature on Culex tarsalis population dynamics." Journal of Medical Entomology, 32(1), 16-27. Foundational degree-day research for western mosquito species.

Limitations & Transparency

⚠️ Important Considerations

Model vs. Observation: Our forecasts are based on a mathematical model, not direct mosquito surveillance. Actual populations may vary due to local factors (standing water, vegetation, land use) not captured in weather data.
No Ground-Truth Validation: Unlike some commercial forecasts, we do not currently have access to mosquito trap data for model validation. We rely on established entomological parameters from peer-reviewed research.
Microclimate Variation: Weather data represents regional conditions. Properties near water bodies, dense vegetation, or urban heat islands may experience higher pressure than indicated.
Species Assumptions: We use regional species profiles, but local species composition may differ. The "mixed population" model is a conservative average.

Continuous Improvement

We are committed to improving forecast accuracy over time. Our accuracy feedback system collects real-world observations from pest control professionals to identify systematic biases and refine model parameters. We welcome partnerships with entomology researchers and mosquito abatement districts for model validation.

API Access

Pressure Forecast data is available via REST API for integration with pest control management software, routing systems, and custom applications.

GET /forecast/mosquito/zip/{zip_code}

Returns 14-day forecast with daily pressure scores, risk categories, and score breakdown by component.

For API documentation and access, contact us or visit api.pressureforecast.com/docs