SoCal Humidity & Dew Point Simulator p5.js Thermodynamic Engine

Demystifying Southern California's humidity surges, marine layer fog, and sweat cooling physics

Active Scenario: Monsoonal Moisture Surge Live Thermodynamic Parcel Particle View
Air Temperature ($T$) 92 °F
Dew Point ($T_d$) 70 °F
Coastal Wind Speed 8 mph
🧠 Why Does SoCal Feel Surprisingly Humid?

Unlike Florida or Houston, Southern California usually enjoys dry summers. However, two distinct weather phenomena trigger unexpected humidity:

  • Monsoonal Moisture Surges: Warm, muggy air sweeps north from the Gulf of California and Tropical Pacific (July–August), driving dew points above 65°F–70°F and making 90°F+ heat feel oppressive.
  • Marine Layer Inversions: Cool Pacific ocean water saturates the surface air (Relative Humidity near 100%), creating June Gloom fog. The temperature stays low (65°F), but dew points are high relative to air temp.
  • Sweat Evaporation Physics: High relative humidity reduces the Vapor Pressure Deficit (VPD). Water molecules cannot easily evaporate from human skin into saturated air, preventing latent heat loss and spiking perceived Heat Index.
Thermodynamic State: Air Temp: 92°F | Dew Point: 70°F | Relative Humidity: 49% | Heat Index: 97°F | Evap Cooling: 51%
Thermodynamic Output Preset: Monsoonal
Extreme Caution Heat Index: 97°F
Relative Humidity 49% Saturation Ratio
Heat Index 97°F Feels Like Temp
Vapor Pressure Deficit 2.28 kPa Drying Potential
Skin Cooling Efficiency 51% Evaporation Rate
Psychrometric Vapor Curve Tetens Equation
Analysis & Export
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