This report describes the typical weather at the Denver International Airport (Denver, Colorado, United States) weather station over the course of an average April 15. It is based on the historical records from 1995 to 2012. Earlier records are either unavailable or unreliable.
Denver, Colorado has a cold semi-arid steppe climate. The area within 25 mi of this station is covered by grasslands (86%), built-up areas (10%), and croplands (3%).
The temperature typically varies from 37°F to 58°F and is rarely below 28°F or above 73°F.
The coolest hours of the day are from 1am to 8am with the coldest at 6am, at which time the temperature is below 43°F three days out of four.
The warmest hours of the day are from noon to 7pm with the hottest at 3pm, at which time the temperature is above 50°F three days out of four.
The day has gained half its heat by 10am and lost it again by 9pm.
On April 15 the Sun rises at 6:20am and sets at 7:37pm.
Solar noon is at 12:58pm.
For reference, on the longest day of the year the Sun rises at 5:30am and sets at 8:30pm, while on the shortest day of the year it rises at 7:17am and sets at 4:37pm.
Astronomical twilight begins and ends 97 minutes before sunrise and after sunset at 4:43am and 9:14pm, respectively.
Nautical twilight begins and ends 61 minutes before sunrise and after sunset at 5:18am and 8:39pm, respectively.
Civil twilight begins and ends 28 minutes before sunrise and after sunset at 5:52am and 8:05pm, respectively.
Solar twilight begins and ends 36 minutes after sunrise and before sunset at 6:56am and 7:01pm, respectively.
The median cloud cover ranges from 61% (partly cloudy) to 83% (mostly cloudy).
At 3am, the clearest time of the day, the sky is clear, mostly clear, or partly cloudy 55% of the time, and overcast or mostly cloudy 45% of the time.
At 6pm, the cloudiest time of the day, the sky is overcast, mostly cloudy, or partly cloudy 86% of the time, and clear or mostly clear 14% of the time.
The sky is typically clearing in earnest by 11pm.
The clouds have typically started forming in earnest by noon.
There is a 37% chance that precipitation will be observed at some point during the day.
The average measured liquid-equivalent quantity of precipitation is 0.053". Among only those days for which there is at least some measured precipitation, the average is 0.167" and the total rarely exceeds 0.365".
When precipitation does occur it is most often in the form of slight snow (33% of days with precipitation have at worst slight snow), thunderstorms (20%), slight rain (18%), moderate snow (16%), and moderate rain (8%).
Precipitation is most likely around 9pm and least likely around noon.
There is a 6% chance that there will be snow on the ground. The average snow depth is 10.2". The snow depth is deeper than 16.0" one year in four and deeper than 22.0" one year in ten.
The relative humidity typically ranges from 35% (comfortable) to 68% (mildly humid), rarely dropping below 13% (very dry), or exceeding 92% (very humid).
The air is driest at 3pm, at which time the relative humidity is less than 47% (comfortable) three days out of four; it is most humid at 5am, exceeding 52% (mildly humid) three days out of four.
The dew point ranges from 24°F to 28°F with an average of 27°F.
For reference, comfortable indoor conditions should have a relative humidity between 30% and 50% with a dew point of less than 65°F.
Sustained wind speeds typically vary from 10 mph to 14 mph (gentle breeze to moderate breeze) over the course of the day.
The peak sustained wind speed typically occurs around 5pm and is rarely outside the range 6 mph to 23 mph (light breeze to fresh breeze).
The wind is most calm around 7am, rarely exceeding 16 mph (moderate breeze).
The wind is most often out of the south (17% of the time), north (15% of the time), south west (15% of the time), and west (11% of the time).