Meteorology Calculators

Frost Date Probability Calculator

Estimate frost probability by date for gardening planning. Calculate first and last frost risk windows from your location and average frost dates.

Wet Bulb Globe Temperature (WBGT) Calculator

Calculate WBGT heat-stress index from temperature, humidity, and sun exposure. Get OSHA work-rest cycles and athlete heat-safety levels for outdoor activity.

CAPE Atmospheric Instability Calculator

Estimate CAPE and Lifted Index from surface temperature, dewpoint, and 500 hPa temperature to assess thunderstorm potential and severe weather risk.

Precipitation Return Period and Exceedance Probability Calculator

Calculate storm return periods and exceedance probabilities. Find the chance a 100-year storm occurs during a structure lifespan for flood frequency analysis.

Snow Water Equivalent (SWE) Calculator

Calculate snow water equivalent from snow depth and density. Find how much liquid water is stored in a snowpack. Results in mm, inches, liters, and gallons.

Solar Radiation on Tilted Surface Calculator

Calculate total solar irradiance on a tilted surface. Find beam, diffuse, and reflected radiation components to optimize solar panel tilt angle and azimuth.

Tornado Enhanced Fujita Scale Wind Speed Estimator

Look up EF tornado scale wind speeds, damage descriptions, and frequencies for any EF0 to EF5 tornado rating. Calculate dynamic pressure and energy comparisons.

Cloud Base Altitude Calculator

Calculate cloud base height above ground (AGL) and mean sea level (MSL) from surface temperature and dew point using the LCL formula. Includes fog indicator.

Rainbow Angle and Geometry Calculator

Calculate rainbow angles and geometry. Find the primary (42 degrees) and secondary (51 degrees) rainbow angles and calculate where to look for a rainbow.

Cooling Degree Days (CDD) Calculator

Calculate cooling degree days to estimate air conditioning energy demand. Plan HVAC costs and compare cooling needs across different climates.

Heating Degree Days (HDD) Calculator

Calculate heating degree days to estimate energy consumption for heating buildings. Compare monthly and seasonal heating demand across different climates.

Fog and Visibility Estimator

Estimate visibility in fog from dew point depression and relative humidity. Understand fog formation conditions and aviation minimums.

Hurricane Storm Surge Estimator

Estimate storm surge height from hurricane category and coastal geometry. Understand surge risk by Saffir-Simpson category for coastal planning.

Lightning Safety Distance Calculator

Calculate your distance from lightning using the flash-to-bang method. How many seconds between flash and thunder equals distance in miles or km.

Air Density Calculator

Calculate the density of air at any temperature, pressure, and humidity. Essential for aerodynamics, aviation, and physics calculations.

Altitude Air Pressure Calculator

Calculate atmospheric air pressure at any altitude using the barometric formula. Useful for aviation, hiking, cooking, and science.

Dew Point Temperature Calculator

Calculate the dew point temperature from air temperature and relative humidity. Understand when condensation, fog, and moisture problems will occur.

Air Quality Index (AQI) Interpreter

Interpret AQI readings on the 0-500 scale for PM2.5, PM10, ozone, and NO2. Returns health category from Good to Hazardous with activity guidance.

Atmospheric Pressure at Altitude Calculator

Calculate atmospheric pressure at any altitude using the barometric formula. Returns Pa, hPa, mmHg, and inHg for aviation, weather, and altitude cooking.

Barometric Altitude Calculator

Estimate altitude from barometric pressure using the hypsometric formula. Returns elevation in feet and meters from pressure readings in hPa, mbar, or inHg.

UV Index Exposure Calculator

Calculate safe sun exposure from UV index, Fitzpatrick skin type, and SPF. Returns minutes to sunburn, protected exposure window, and vitamin D synthesis time.

Wind Speed Beaufort Scale Calculator

Convert wind speed in mph, km/h, or knots to Beaufort scale (0-12). Shows land and sea conditions, observed effects, and outdoor safety warnings for each level.

Boiling Point at Altitude Calculator

Calculate the boiling point of water at any altitude. At 5,000 ft water boils at 202°F; at 10,000 ft just 194°F — see how elevation affects cooking time.

Dew Point Calculator

Calculate the dew point from temperature and relative humidity. See comfort level and condensation risk. Supports Fahrenheit and Celsius.

Heat Index Calculator

Calculate the feels-like temperature based on air temperature and relative humidity. Includes danger level warnings for heat-related illness.

Pool Evaporation Calculator

Estimate daily pool water loss to evaporation from pool surface area, water temperature, air humidity, and wind speed. Returns gallons and liters lost per day.

Pressure at Altitude Calculator

Calculate atmospheric pressure at any altitude using the barometric formula. Enter elevation in feet or meters to get pressure in hPa, mb, inHg, and psi.

Relative Humidity Calculator

Calculate relative humidity from dry bulb and wet bulb temperatures. Supports Fahrenheit and Celsius with psychrometric formulas.

Wind Chill Calculator

Calculate the wind chill (feels-like) temperature from air temperature and wind speed. Supports Fahrenheit/Celsius and mph/km/h.