Climate and Average Weather Year Round in New Castle Colorado, United States
In New Castle, the summers are warm and mostly clear, the winters are freezing and partly cloudy, and it is dry year round. Over the course of the year, the temperature typically varies from 12°F to 87°F and is rarely below -2°F or above 93°F.
Based on the tourism score, the best time of year to visit New Castle for warm-weather activities is from late June to late August.
Climate in New Castle
Average Temperature in New Castle
The hot season lasts for 3.4 months, from June 2 to September 15, with an average daily high temperature above 76°F. The hottest day of the year is July 12, with an average high of 87°F and low of 53°F.
The cold season lasts for 3.1 months, from November 22 to February 25, with an average daily high temperature below 44°F. The coldest day of the year is January 7, with an average low of 12°F and high of 33°F.
Average High and Low Temperature in New Castle
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 in New Castle
In New Castle, 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 in New Castle begins around May 30 and lasts for 5.0 months, ending around October 30. On September 13, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 77% of the time, and overcast or mostly cloudy 23% of the time.
The cloudier part of the year begins around October 30 and lasts for 7.0 months, ending around May 30. On February 21, the cloudiest day of the year, the sky is overcast or mostly cloudy 49% of the time, and clear, mostly clear, or partly cloudy 51% of the time.
Cloud Cover Categories in New Castle
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 in New Castle varies throughout the year.
The wetter season lasts 10 months, from July 9 to May 23, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 24% on May 1.
The drier season lasts 1.5 months, from May 23 to July 9. The smallest chance of a wet day is 12% on June 19.
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 in New Castle changes throughout the year.
Rain alone is the most common for 9.5 months, from February 11 to November 28. The highest chance of a day with rain alone is 23% on August 1.
Snow alone is the most common for 2.1 months, from December 1 to February 2. The highest chance of a day with snow alone is 8% on December 29.
Mixed snow and rain is the most common for 1.7 weeks, from February 2 to February 11 and from November 28 to December 1. The highest chance of a day with mixed snow and rain is 6% on February 24.
Daily Chance of Precipitation in New Castle
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. New Castle experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 10 months, from February 9 to December 9, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around September 30, with an average total accumulation of 1.4 inches.
The rainless period of the year lasts for 2.0 months, from December 9 to February 9. The least rain falls around January 17, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall in New Castle
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. New Castle experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 5.4 months, from October 24 to April 7, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 3, with an average total liquid-equivalent accumulation of 0.5 inches.
The snowless period of the year lasts for 6.5 months, from April 7 to October 24. The least snow falls around July 28, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall in New Castle
The length of the day in New Castle varies significantly over the course of the year. In 2021, the shortest day is December 21, with 9 hours, 22 minutes of daylight; the longest day is June 20, with 14 hours, 58 minutes of daylight.
Hours of Daylight and Twilight in New Castle
The earliest sunrise is at 5:42 AM on June 13, and the latest sunrise is 2 hours, 2 minutes later at 7:44 AM on November 6. The earliest sunset is at 4:45 PM on December 7, and the latest sunset is 3 hours, 56 minutes later at 8:41 PM on June 27.
Daylight saving time (DST) is observed in New Castle during 2021, starting in the spring on March 14, lasting 7.8 months, and ending in the fall on November 7.
Sunrise & Sunset with Twilight and Daylight Saving Time in New Castle
The figure below presents a compact representation of key lunar data for 2021. 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.
Moon Rise, Set & Phases in New Castle
The perceived humidity level in New Castle, 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 in New Castle
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in New Castle experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 4.4 months, from February 15 to June 29, with average wind speeds of more than 6.1 miles per hour. The windiest day of the year is April 4, with an average hourly wind speed of 7.0 miles per hour.
The calmer time of year lasts for 7.6 months, from June 29 to February 15. The calmest day of the year is August 7, with an average hourly wind speed of 5.1 miles per hour.
Average Wind Speed in New Castle
The predominant average hourly wind direction in New Castle varies throughout the year.
The wind is most often from the west for 6.8 months, from March 11 to October 5, with a peak percentage of 42% on June 23. The wind is most often from the south for 5.2 months, from October 5 to March 11, with a peak percentage of 49% on January 1.
Wind Direction in New Castle
Best Time of Year to Visit
To characterize how pleasant the weather is in New Castle 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 New Castle for general outdoor tourist activities is from late June to late August, with a peak score in the last week of July.
Tourism Score in New Castle
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 New Castle for hot-weather activities is from late June to mid August, with a peak score in the second week of July.
Beach/Pool Score in New Castle
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 in New Castle typically lasts for 4.6 months (140 days), from around May 13 to around September 30, rarely starting before April 24 or after June 2, and rarely ending before September 11 or after October 20.
Time Spent in Various Temperature Bands and the Growing Season in New Castle
Based on growing degree days alone, the first spring blooms in New Castle should appear around April 22, only rarely appearing before April 8 or after May 6.
Growing Degree Days in New Castle
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 2.5 months, from May 14 to July 30, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest day of the year is June 17, with an average of 8.3 kWh.
The darker period of the year lasts for 3.4 months, from November 1 to February 13, with an average daily incident shortwave energy per square meter below 3.6 kWh. The darkest day of the year is December 21, with an average of 2.4 kWh.
Average Daily Incident Shortwave Solar Energy in New Castle
For the purposes of this report, the geographical coordinates of New Castle are 39.573 deg latitude, -107.536 deg longitude, and 5,587 ft elevation.
The topography within 2 miles of New Castle contains very significant variations in elevation, with a maximum elevation change of 1,673 feet and an average elevation above sea level of 5,950 feet. Within 10 miles contains very significant variations in elevation (5,469 feet). Within 50 miles also contains extreme variations in elevation (9,308 feet).
The area within 2 miles of New Castle is covered by shrubs (69%) and trees (19%), within 10 miles by trees (52%) and shrubs (39%), and within 50 miles by trees (55%) and shrubs (37%).
This report illustrates the typical weather in New Castle, 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 New Castle.
For each station, the records are corrected for the elevation difference between that station and New Castle 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 New Castle is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between New Castle and a given station.
The stations contributing to this reconstruction are: Garfield County Regional Airport (KRIL, 86%, 17 kilometers, west); Sunlight (K5SM, 3.0%, 20 kilometers, southeast); and Meeker Airport (KEEO, 11%, 61 kilometers, northwest).
Time zones for airports and weather stations are provided by AskGeo.com .