Mostly cloudy. The resulting altimeter readings are known as flight levels. West wind 5 to 10 mph becoming east northeast in the afternoon. Providing local NWS alerts, warnings, and advisories for the area and overall Denver county, Colorado. Detailed Weather Forecast for April 15 in Denver, Colorado, United States - temperature, wind, atmospheric pressure, humidity and precipitations - World-Weather.info. However, the inch of mercury is still used today in car performance modification to measure the amount of vacuum or pressure within the engine's intake manifold. c. psi. The answer is 0.033421060942512. Type in your own numbers in the form to convert the units!