National Weather Service United States Department of Commerce

Heavy snow in the Rockies, Fire weather threat in the Southwest, and Heavy rainfall threat for the weekend in the Southern Plains into the Ohio Valley

Heavy snow is expected in the northern and central Rockies. There is a critical to elevated fire risk across the Southwest. A few severe storms are expected from the Southeast States into the Great Lakes and portions of the Central Plains on Thursday. Heavy rainfall is forecast through the weekend with a threat for significant flooding for the Southern Plains into the Mississippi Valley Read More >


 
 

Temperature Conversion

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

Celsius
(o 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
(o 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
(o 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 (o F)

RH

HI

Tdp

OR

Temp (o F)

Tdp

HI RH

Station Pressure Calculation

What is the current altimeter (inches)?
What is the station elevation? (feet)
i.e. St. Louis - Lambert= 710
The Station Pressure in inches is:
The Station Pressure in millibars is:
The Pressure Altitude in feet is: