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April Weather in Casper Wyoming, United States

Daily high temperatures increase by 8°F, from 54°F to 62°F, rarely falling below 38°F or exceeding 77°F.

Daily low temperatures increase by 7°F, from 29°F to 36°F, rarely falling below 18°F or exceeding 46°F.

For reference, on July 18, the hottest day of the year, temperatures in Casper typically range from 57°F to 88°F, while on December 29, the coldest day of the year, they range from 17°F to 34°F.

Average High and Low Temperature in April in Casper

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on April. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in April in Casper

Average Hourly Temperature in April in CasperApr11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMMarMayfreezingfreezingvery coldcoldcoolcomfortable
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Elmadağ, Turkey (6,190 miles away); Hozat, Turkey (6,383 miles); and Bījār, Iran (6,761 miles) are the far-away foreign places with temperatures most similar to Casper (view comparison).

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The month of April in Casper experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 51% throughout the month.

The clearest day of the month is April 27, with clear, mostly clear, or partly cloudy conditions 51% of the time.

For reference, on March 20, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 53%, while on July 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 77%.

Cloud Cover Categories in April in Casper

Cloud Cover Categories in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%MarMayApr 148%Apr 148%Apr 3050%Apr 3050%Apr 1149%Apr 1149%Apr 2150%Apr 2150%clearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Casper, the chance of a wet day over the course of April is rapidly increasing, starting the month at 15% and ending it at 23%.

For reference, the year's highest daily chance of a wet day is 27% on May 22, and its lowest chance is 5% on January 10.

Over the course of April in Casper, the chance of a day with only rain increases from 7% to 19%, the chance of a day with mixed snow and rain remains an essentially constant 4% throughout, and the chance of a day with only snow decreases from 3% to 1%.

Probability of Precipitation in April in Casper

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during April in Casper is increasing, starting the month at 0.5 inches, when it rarely exceeds 1.0 inches or falls below 0.1 inches, and ending the month at 1.4 inches, when it rarely exceeds 2.6 inches or falls below 0.4 inches.

Average Monthly Rainfall in April in Casper

Average Monthly Rainfall in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300.0 in0.0 in0.5 in0.5 in1.0 in1.0 in1.5 in1.5 in2.0 in2.0 in2.5 in2.5 in3.0 in3.0 in3.5 in3.5 inMarMayApr 10.5 inApr 10.5 inApr 301.4 inApr 301.4 inApr 110.8 inApr 110.8 inApr 211.1 inApr 211.1 in
The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day snowfall during April in Casper is decreasing, starting the month at 3.2 inches, when it rarely exceeds 7.7 inches, and ending the month at 1.6 inches, when it rarely exceeds 4.6 inches or falls below -0.0 inches.

Average Monthly Snowfall in April in Casper

The average snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Over the course of April in Casper, the length of the day is rapidly increasing. From the start to the end of the month, the length of the day increases by 1 hour, 20 minutes, implying an average daily increase of 2 minutes, 45 seconds, and weekly increase of 19 minutes, 15 seconds.

The shortest day of the month is April 1, with 12 hours, 46 minutes of daylight and the longest day is April 30, with 14 hours, 6 minutes of daylight.

Hours of Daylight and Twilight in April in Casper

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The latest sunrise of the month in Casper is 6:46 AM on April 1 and the earliest sunrise is 46 minutes earlier at 5:59 AM on April 30.

The earliest sunset is 7:32 PM on April 1 and the latest sunset is 33 minutes later at 8:05 PM on April 30.

Daylight saving time is observed in Casper during 2024, but it neither starts nor ends during April, so the entire month is in daylight saving time.

For reference, on June 20, the longest day of the year, the Sun rises at 5:26 AM and sets 15 hours, 21 minutes later, at 8:47 PM, while on December 21, the shortest day of the year, it rises at 7:33 AM and sets 9 hours, 1 minute later, at 4:34 PM.

Sunrise & Sunset with Twilight and Daylight Saving Time in April in Casper

Sunrise & Sunset with Twilight and Daylight Saving Time in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930302 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMMarMay5:59 AM5:59 AMApr 308:05 PMApr 308:05 PM6:46 AM6:46 AMApr 17:32 PMApr 17:32 PM6:29 AM6:29 AMApr 117:43 PMApr 117:43 PMSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of April. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in April in Casper

Solar Elevation and Azimuth in April in CasperApr11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMMarMay001010202020303040405050600001010202030303040405060
northeastsouthwest
Solar elevation and azimuth over the course of April 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for April 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.

Moon Rise, Set & Phases in April in Casper

Moon Rise, Set & Phases in April in CasperApr11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMMarMayMar 103:01 AMMar 103:01 AMMar 251:01 AMMar 251:01 AMApr 812:22 PMApr 812:22 PMApr 235:50 PMApr 235:50 PMMay 79:23 PMMay 79:23 PMMay 237:54 AMMay 237:54 AM7:45 AM7:45 AM7:50 PM7:50 PM7:02 PM7:02 PM7:12 AM7:12 AM6:31 AM6:31 AM8:00 PM8:00 PM8:02 PM8:02 PM6:16 AM6:16 AM5:20 AM5:20 AM8:13 PM8:13 PM8:06 PM8:06 PM5:15 AM5:15 AM
The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.
Apr 2024IlluminationMoonriseMoonsetMoonriseMeridian PassingDistance
1
50%2:37 AMSE10:54 AMSW-6:45 AMS237,560 mi
2
45%3:31 AMSE12:01 PMSW-7:46 AMS234,191 mi
3
34%4:15 AMSE1:17 PMWSW-8:46 AMS230,828 mi
4
23%4:50 AMESE2:37 PMWSW-9:44 AMS227,735 mi
5
13%5:19 AMESE3:58 PMWSW-10:38 AMS225,212 mi
6
6%5:45 AMESE5:19 PMW-11:30 AMS223,551 mi
7
1%6:08 AME6:39 PMW-12:21 PMS222,980 mi
8
0%6:31 AME8:00 PMWNW-1:11 PMS223,616 mi
9
2%6:55 AMENE9:21 PMWNW-2:03 PMS225,433 mi
10
6%7:23 AMENE10:42 PMWNW-2:57 PMS228,263 mi
11
13%7:57 AMENE--3:53 PMS231,824 mi
12
22%-12:00 AMNW8:38 AMNE4:51 PMS235,767 mi
13
32%-1:10 AMNW9:29 AMNE5:49 PMS239,738 mi
14
42%-2:09 AMNW10:28 AMNE6:45 PMS243,424 mi
15
50%-2:56 AMNW11:33 AMNE7:37 PMS246,585 mi
16
63%-3:32 AMNW12:39 PMENE8:25 PMS249,067 mi
17
72%-4:01 AMWNW1:45 PMENE9:09 PMS250,797 mi
18
80%-4:24 AMWNW2:49 PMENE9:50 PMS251,772 mi
19
87%-4:44 AMWNW3:51 PME10:30 PMS252,040 mi
20
93%-5:02 AMW4:53 PME11:08 PMS251,685 mi
21
97%-5:19 AMW5:55 PME11:47 PMS250,810 mi
22
99%-5:36 AMW6:57 PMESE--
23
100%-5:55 AMWSW8:02 PMESE12:27 AMS249,520 mi
24
100%-6:16 AMWSW9:09 PMESE1:10 AMS247,907 mi
25
98%-6:42 AMWSW10:18 PMSE1:56 AMS246,047 mi
26
94%-7:14 AMSW11:27 PMSE2:46 AMS243,992 mi
27
89%-7:56 AMSW-3:41 AMS241,776 mi
28
81%12:31 AMSE8:48 AMSW-4:40 AMS239,420 mi
29
72%1:27 AMSE9:52 AMSW-5:39 AMS236,955 mi
30
61%2:14 AMSE11:04 AMSW-6:39 AMS234,435 mi

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in Casper is essentially constant during April, remaining around 0% throughout.

Humidity Comfort Levels in April in Casper

Humidity Comfort Levels in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%MarMayApr 160%Apr 160%Apr 10%Apr 10%Apr 300%Apr 300%drydry
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Casper is decreasing during April, decreasing from 12.0 miles per hour to 10.7 miles per hour over the course of the month.

For reference, on January 9, the windiest day of the year, the daily average wind speed is 15.4 miles per hour, while on August 2, the calmest day of the year, the daily average wind speed is 8.6 miles per hour.

Average Wind Speed in April in Casper

The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The hourly average wind direction in Casper throughout April is predominantly from the west, with a peak proportion of 52% on April 2.

Wind Direction in April in Casper

Wind Direction in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%20%80%40%60%60%40%80%20%100%0%MarMaywestnorthsoutheast
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Casper typically lasts for 4.3 months (134 days), from around May 14 to around September 25, rarely starting before April 25 or after May 31, and rarely ending before September 7 or after October 13.

The month of April in Casper is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season increasing from 0% to 17% over the course of the month.

Time Spent in Various Temperature Bands and the Growing Season in April in Casper

Time Spent in Various Temperature Bands and the Growing Season in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%MarMayApr 10%Apr 10%Apr 3017%Apr 3017%Apr 112%Apr 112%Apr 216%Apr 216%50%May 1450%May 1490%May 3190%May 31freezingvery coldcoldcoolcomfortablewarmfrigid
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days in Casper are gradually increasing during April, increasing by 86°F, from 38°F to 124°F, over the course of the month.

Growing Degree Days in April in Casper

Growing Degree Days in April in CasperApr11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303020°F20°F40°F40°F60°F60°F80°F80°F100°F100°F120°F120°F140°F140°F160°F160°F180°F180°F200°F200°FMarMayApr 138°FApr 138°FApr 30124°FApr 30124°FApr 1160°FApr 1160°FApr 2190°FApr 2190°F
The average growing degree days accumulated over the course of April, with 25th to 75th and 10th to 90th percentile bands.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy in Casper is increasing during April, rising by 1.1 kWh, from 5.4 kWh to 6.4 kWh, over the course of the month.

Average Daily Incident Shortwave Solar Energy in April in Casper

Average Daily Incident Shortwave Solar Energy in April in CasperApr1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWhMarMayApr 15.4 kWhApr 15.4 kWhApr 306.4 kWhApr 306.4 kWhApr 115.7 kWhApr 115.7 kWh
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

For the purposes of this report, the geographical coordinates of Casper are 42.867 deg latitude, -106.313 deg longitude, and 5,171 ft elevation.

The topography within 2 miles of Casper contains only modest variations in elevation, with a maximum elevation change of 289 feet and an average elevation above sea level of 5,195 feet. Within 10 miles contains only modest variations in elevation (3,153 feet). Within 50 miles contains large variations in elevation (4,823 feet).

The area within 2 miles of Casper is covered by shrubs (76%), artificial surfaces (12%), and grassland (12%), within 10 miles by grassland (48%) and shrubs (41%), and within 50 miles by shrubs (57%) and grassland (39%).

This report illustrates the typical weather in Casper, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Casper.

For each station, the records are corrected for the elevation difference between that station and Casper according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Casper is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Casper and a given station.

The stations contributing to this reconstruction are:

To get a sense of how much these sources agree with each other, you can view a comparison of Casper and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © OpenStreetMap contributors.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.

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