Weather & Environment Calculators
Understand the weather conditions around you with our free weather and environment calculators. Calculate the real-feel temperature using heat index or wind chill, find the dew point for comfort assessment, estimate rainfall and humidity levels, measure your carbon footprint, plan rainwater harvesting, or convert between temperature scales. All tools run instantly in your browser with no sign-up required.
Temperature & Comfort
How hot or cold it really feels outside.
Heat Index Calculator
Calculate the apparent temperature from heat and humidity.
Wind Chill Calculator
Find how cold it feels based on temperature and wind speed.
Dew Point Calculator
Calculate the dew point from temperature and relative humidity.
Humidity Calculator
Convert between relative humidity, absolute humidity, and dew point.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin.
Precipitation & Water
Rainfall measurement and rainwater collection tools.
Rainfall Calculator
Calculate total rainfall volume from depth and area.
Rainwater Harvesting Calculator
Estimate how much rainwater you can collect from your roof.
Environment
Track and reduce your environmental impact.
Frequently Asked Questions
What is the heat index and how is it calculated?
The heat index, also called the apparent temperature, combines air temperature and relative humidity to indicate how hot it actually feels. When humidity is high, sweat evaporates more slowly, making you feel hotter. The Rothfusz regression equation used by the National Weather Service calculates the heat index from temperature and humidity inputs. Our calculator shows the result in both Fahrenheit and Celsius.
What is dew point and why does it matter?
The dew point is the temperature at which air becomes saturated and water vapor begins to condense into dew or fog. A higher dew point means more moisture in the air and greater discomfort. Dew points above 65°F (18°C) feel muggy, and above 70°F (21°C) feel oppressive. Our calculator derives dew point from temperature and relative humidity using the Magnus-Tetens approximation.
How is wind chill calculated?
Wind chill measures how cold it feels on exposed skin when the wind blows. The current NWS wind chill formula takes air temperature (below 50°F / 10°C) and wind speed (above 3 mph) and calculates the equivalent calm-air temperature. Higher wind speeds cause heat to leave the body faster, making it feel colder than the actual temperature.
How can I calculate my carbon footprint?
A carbon footprint calculator estimates your annual CO2 emissions from energy use (electricity, natural gas), transportation (car miles, flights), diet, and waste. The average American produces about 16 metric tons of CO2 per year. Our calculator breaks down emissions by category and suggests areas where you can reduce your impact.