National Weather Service United States Department of Commerce

Heat and Fire Weather Concerns West; Heavy Rain and Thunderstorms from Plains to mid-Atlantic

Thunderstorms and locally heavy rainfall is expected from the Central Plains to the Ohio Valley, mid-Atlantic and across the Southeast. Severe weather from the Upper Midwest to Central Plains increases on Friday. Major to Extreme HeatRisk continues across the Southern Plains to the lower Mississippi Valley late this week. Fire weather concerns for the northern Rockies and northern Plains today. Read More >

National Weather Service Hanford, CA
Meteorological Calculator
Thanks to Ron Murphy, NWS Birmingham, AL for writing the JavaScript.

Temperature Conversion

Enter a number then click on the the conversion button.
Fahrenheit
(F)

Celsius
(C)

Wind Speed Calculations

Enter a speed into any blank to convert to all other wind speeds.

 mph    knots       m/sec      km/hr  

Wind Chill Calculation

Enter the temperature in degrees Fahrenheit and wind speed in mph, then click on the Calculate WC to compute the windchill index.
Temp
(F)

Wind
(mph)

Index 

Relative Humidity Calculation

Enter the air temperature and the dew point in degrees Fahrenheit, then click on the Calculate RH to compute the relative humidity.
Temp
(F)

Dew
Point

Heat Index Calculations

Enter the temperature in degrees Fahrenheit and relative humidity (RH) in percent (without the % sign), or the Dew Point (Tdp).  Then click on the Calculate HI to compute the heat index (HI).
Temp (F)

RH

HI 

Tdp

OR

Temp (F)

Tdp

HI  RH 

Station Pressure Calculation

What is the current altimeter (inches)?
What is the station elevation? (feet)
i.e. Fresno Air Terminal = 333
The Station Pressure in inches is:
The Station Pressure in millibars is:
The Pressure Altitude in feet is: