Average Weather at Sibley Peak Wyoming, United States
At Sibley Peak, the summers are hot and mostly clear; the winters are very cold, windy, and partly cloudy; and it is dry year round. Over the course of the year, the temperature typically varies from 18°F to 90°F and is rarely below -0°F or above 98°F.
Based on the tourism score, the best time of year to visit Sibley Peak for warm-weather activities is from late June to late August.
The hot season lasts for 3.0 months, from June 13 to September 12, with an average daily high temperature above 80°F. The hottest day of the year is July 25, with an average high of 90°F and low of 61°F.
The cold season lasts for 3.6 months, from November 17 to March 6, with an average daily high temperature below 50°F. The coldest day of the year is January 1, with an average low of 18°F and high of 40°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
At Sibley Peak, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year at Sibley Peak begins around June 6 and lasts for 4.2 months, ending around October 13. On July 4, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 76% of the time, and overcast or mostly cloudy 24% of the time.
The cloudier part of the year begins around October 13 and lasts for 7.8 months, ending around June 6. On March 28, the cloudiest day of the year, the sky is overcast or mostly cloudy 52% of the time, and clear, mostly clear, or partly cloudy 48% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Sibley Peak varies throughout the year.
The wetter season lasts 4.1 months, from April 11 to August 14, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 32% on May 24.
The drier season lasts 7.9 months, from August 14 to April 11. The smallest chance of a wet day is 4% on January 14.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation at Sibley Peak changes throughout the year.
Rain alone is the most common for 9.3 months, from February 19 to November 29. The highest chance of a day with rain alone is 31% on May 25.
Snow alone is the most common for 2.7 months, from November 29 to February 19. The highest chance of a day with snow alone is 3% on December 14.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Sibley Peak experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.3 months, from March 25 to November 3, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around May 23, with an average total accumulation of 2.1 inches.
The rainless period of the year lasts for 4.7 months, from November 3 to March 25. The least rain falls around January 2, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall at Sibley Peak does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day at Sibley Peak varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 4 minutes of daylight; the longest day is June 21, with 15 hours, 18 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:22 AM on June 14, and the latest sunrise is 2 hours, 14 minutes later at 7:36 AM on November 3. The earliest sunset is at 4:27 PM on December 7, and the latest sunset is 4 hours, 14 minutes later at 8:41 PM on June 26.
Daylight saving time (DST) is observed at Sibley Peak during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level at Sibley Peak, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed at Sibley Peak experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 5.5 months, from October 30 to April 14, with average wind speeds of more than 12.4 miles per hour. The windiest day of the year is January 17, with an average hourly wind speed of 16.0 miles per hour.
The calmer time of year lasts for 6.5 months, from April 14 to October 30. The calmest day of the year is July 26, with an average hourly wind speed of 8.8 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Sibley Peak is from the west throughout the year.
Best Time of Year to Visit
To characterize how pleasant the weather is at Sibley Peak throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Sibley Peak for general outdoor tourist activities is from late June to late August, with a peak score in the second week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Sibley Peak for hot-weather activities is from early July to mid August, with a peak score in the last week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season at Sibley Peak typically lasts for 5.1 months (155 days), from around May 5 to around October 7, rarely starting before April 14 or after May 22, and rarely ending before September 18 or after October 27.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms at Sibley Peak should appear around April 10, only rarely appearing before March 25 or after April 28.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.0 months, from May 12 to August 13, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest day of the year is July 3, with an average of 7.9 kWh.
The darker period of the year lasts for 3.4 months, from October 30 to February 12, with an average daily incident shortwave energy per square meter below 3.2 kWh. The darkest day of the year is December 21, with an average of 2.0 kWh.
Average Daily Incident Shortwave Solar Energy
This report illustrates the typical weather at Sibley Peak, 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
Sibley Peak has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Converse County Airport, Torrington Municipal Airport, Laramie Regional Airport, Cheyenne Airport, Casper–Natrona County International Airport, Western Nebraska Regional Airport, Kimball Municipal Airport-Robert E Arraj Field, and Custer County Airfield.
Time zones for aiports and weather stations are provided by AskGeo.com .