National Weather Service United States Department of Commerce

Cold Temperatures and Some Snow

A strong cold front and low pressure system will press from the Central U.S. through the East over the next couple of days. The impressive cold front will allow a cold air mass to settle in east of the Rockies and numerous record low temperatures are likely the next few days, especially Wednesday morning. A streak of snow is also expected from the central Plains to northern New England. 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: