The dew point is the temperature at which , when reached, dew will form. 
That will take place on this graph when the blue line crosses into the pink area.

If the dewpoint is below zero degrees and it is reached, then frost ( or hoarfrost ) will form.The given dewpoint at any time is 
calculated from a combination of humidity and air pressure and is in effect a measurement of how saturated the air is with water.
 Barometric Pressure is the amount of downward force exerted by 
the weight of the air above and is measured in hectopascal which is equivalent to the older unit millibar (mbar).
Wind Speed is the average velocity at which the air travels over a one-minute 
period and is measured in miles per hour .

Speed   Description	
< 1	Calm		
1-4	Light air	
5-7	Light breeze	                      
8-11	Gentle breeze	
12-18	Moderate breeze	
19-24	Fresh breeze	
25-31	Strong breeze	
32-38	Near gale	
39-46	Gale	Moderate
47-54	Strong gale	
55-63	Storm	Very hig
64-73	Violent storm˙	
74+	Hurricane Rain fallen over the last hour
Is a measure of the amount of water vapour content of the air, where 100%= the dew point, i.e
 the atmosphere is saturated with water and water begins to condense.
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