Weather

Hurricane Category Calculator (Saffir-Simpson Scale)

Determine the hurricane category from wind speed using the Saffir-Simpson Hurricane Wind Scale. See expected damage, storm surge, and safety guidance.

Tornado Scale Calculator (Enhanced Fujita Scale)

Determine the EF rating of a tornado from estimated wind speed. See damage descriptions, frequency statistics, and historical comparisons.

Frost Point Calculator

Calculate the frost point temperature from air temperature and relative humidity. Find out whether frost will form on surfaces overnight.

Snow Water Equivalent Calculator

Calculate how much liquid water is contained in a given depth of snow. Essential for hydrology, agriculture, and flood risk assessment.

Evapotranspiration Calculator

Estimate daily evapotranspiration (ET) for your garden or farm. Calculate how much water plants lose to heat, wind, and humidity each day.

Snow Water Equivalent Calculator

Calculate the water content of snow (SWE). Find how many millimeters or inches of water are stored in a given snow depth based on snow density.

Cloud Base Altitude Calculator

Calculate cloud base altitude in feet and meters from surface temperature and dew point using the 400 ft per degree Fahrenheit formula.

Growing Degree Days (GDD) Calculator

Calculate growing degree days (GDD = ((Tmax + Tmin)/2) - base) for crops from daily high and low temps. Returns cumulative GDD for planting timing.

Roof Snow Load Calculator

Calculate snow weight on your roof in psf from snowfall depth and snow type. Compares load against typical residential limits to assess structural safety.

Wildfire Risk Calculator

Calculate wildfire risk level based on humidity, wind speed, drought duration, vegetation type, and temperature. Get a Low to Extreme risk rating.

Air Quality Index Calculator

Calculate Air Quality Index (AQI) from PM2.5, PM10, and ozone. Returns AQI category from Good (0-50) to Hazardous (301+) with health guidance for each level.

Outdoor Event Weather Risk Calculator

Assess weather risk for outdoor events from temperature, rain, wind, and humidity. Returns a risk score from low to extreme for weddings, sports, and festivals.

Wind Power Potential Calculator

Calculate theoretical wind power output based on wind speed, rotor diameter, and air density. Includes Betz limit for practical maximum.

Heat Index Calculator

Calculate the heat index (feels-like temperature) from air temperature and humidity. Includes danger thresholds from Caution to Extreme Danger in F and C.

Tornado Distance Calculator (Flash-to-Bang)

Estimate tornado or storm distance using the flash-to-bang method. Calculate how far away lightning and severe weather are.

UV Exposure Time Calculator

Calculate safe sun exposure from UV index and Fitzpatrick skin type (I-VI). Returns time to sunburn without protection and with SPF 30 and SPF 50.

Wind Chill and Heat Index Calculator

Calculate wind chill from temperature and wind speed, or heat index from temperature and humidity. Returns the feels-like temperature in Fahrenheit and Celsius.

Wind Chill Calculator

Calculate wind chill in °F or °C from air temperature and wind speed. Returns NWS formula result and frostbite risk time at 30-minute intervals.

Barometric Pressure Converter

Convert barometric pressure between inHg, hPa, millibar, atm, and psi. Includes a weather forecast guide for high, normal, and low pressure readings.

Dew Point Calculator

Calculate the dew point temperature from air temperature and relative humidity. Understand comfort levels and condensation risk.

Frost Date Planting Calculator

Calculate safe planting dates from your last spring frost date. Returns when to start seeds indoors, transplant outdoors, and which crops to direct sow.

Humidity Comfort Index Calculator

Check if your indoor or outdoor humidity is in the comfort zone. Get health and comfort recommendations based on relative humidity.

Lightning Distance Calculator

Calculate lightning strike distance in miles and km by counting seconds between flash and thunder. Returns distance and 30-30 rule shelter guidance.

Rainfall Volume Calculator

Calculate total water volume from rainfall on a given area. Useful for rainwater harvesting, irrigation, and drainage planning.

Snowfall Accumulation Calculator

Estimate snowfall accumulation from precipitation amounts and air temperature. Convert snow depth to snow water equivalent using typical snow density ratios.

UV Index Exposure Calculator

Calculate safe sun exposure time from UV index level 1-11 and Fitzpatrick skin type. Returns time to first burn, sunscreen need, and clothing recommendations.

Carbon Offset Cost Calculator

Calculate carbon offset cost from your annual CO2 tons and market price per ton. Covers flights, driving, home energy, and total lifestyle offset amounts.

Feels Like Temperature Calculator

Calculate feels-like temperature using heat index or wind chill from actual temperature, humidity, and wind speed. Covers both Fahrenheit and Celsius input.

Wind Speed Converter

Convert wind speed between Beaufort scale, mph, km/h, knots, and m/s. Includes Beaufort reference from calm to hurricane force with land and sea descriptions.