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Average Weather in Jamestown Kentucky, United States

In Jamestown, the summers are long, warm, and muggy; the winters are chilly; and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 27°F to 86°F and is rarely below 11°F or above 93°F.

The hot season lasts for 3.9 months, from May 24 to September 22, with an average daily high temperature above 78°F. The hottest day of the year is July 21, with an average high of 86°F and low of 67°F.

The cold season lasts for 2.9 months, from November 28 to February 26, with an average daily high temperature below 53°F. The coldest day of the year is January 29, with an average low of 27°F and high of 44°F.

Average High and Low Temperature

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 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

Average Hourly Temperature in Jamestown12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDecfreezingchillycoldcoolcomfortablewarm
The average hourly temperature, color coded into bands: frigid < 15°F < freezing < 32°F < chilly < 45°F < cold < 55°F < cool < 65°F < comfortable < 75°F < warm < 85°F < hot < 95°F < sweltering. The shaded overlays indicate night and civil twilight.

Clouds

In Jamestown, 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 Jamestown begins around June 14 and lasts for 4.9 months, ending around November 11. On September 21, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 67% of the time, and overcast or mostly cloudy 33% of the time.

The cloudier part of the year begins around November 11 and lasts for 7.1 months, ending around June 14. On January 5, the cloudiest day of the year, the sky is overcast or mostly cloudy 59% of the time, and clear, mostly clear, or partly cloudy 41% of the time.

Cloud Cover

Cloud Cover in Jamestownclearercloudiercloudier0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 559%Jan 559%Sep 2133%Sep 2133%Jun 1446%Jun 1446%Nov 1146%Nov 1146%overcastmostly cloudypartly cloudymostly clearclear
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Jamestown varies throughout the year.

The wetter season lasts 5.0 months, from March 21 to August 20, with a greater than 34% chance of a given day being a wet day. The chance of a wet day peaks at 43% on June 30.

The drier season lasts 7.0 months, from August 20 to March 21. The smallest chance of a wet day is 24% on October 12.

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 throughout the year is rain alone, with a peak probability of 43% on June 30.

Daily Chance of Precipitation

Daily Chance of Precipitation in Jamestownwetdrydry0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJun 3043%Jun 3043%Oct 1224%Oct 1224%Jan 127%Jan 127%Mar 2134%Mar 2134%Aug 2034%Aug 2034%mixedrain
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 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. Jamestown experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Jamestown. The most rain falls during the 31 days centered around May 4, with an average total accumulation of 4.6 inches.

The least rain falls around October 20, with an average total accumulation of 2.9 inches.

Average Monthly Rainfall

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 liquid-equivalent snowfall.

Snowfall

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. Jamestown experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 3.5 months, from November 29 to March 14, 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 25, with an average total liquid-equivalent accumulation of 0.3 inches.

The snowless period of the year lasts for 8.5 months, from March 14 to November 29. The least snow falls around July 24, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall in Jamestownsnowsnow0 in1 in2 in3 in4 in5 inJanFebMarAprMayJunJulAugSepOctNovDecJan 250.3 inJan 250.3 inJul 240.0 inJul 240.0 inNov 290.1 inNov 290.1 inMar 140.1 inMar 140.1 in
The average liquid-equivalent 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.

Sun

The length of the day in Jamestown varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 37 minutes of daylight; the longest day is June 21, with 14 hours, 42 minutes of daylight.

Hours of Daylight and Twilight

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 earliest sunrise is at 5:20 AM on June 12, and the latest sunrise is 1 hour, 48 minutes later at 7:07 AM on November 4. The earliest sunset is at 4:23 PM on December 6, and the latest sunset is 3 hours, 41 minutes later at 8:03 PM on June 28.

Daylight saving time (DST) is observed in Jamestown during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time in Jamestown12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDecJun 125:20 AMJun 125:20 AM8:03 PMJun 288:03 PMJun 28Dec 64:23 PMDec 64:23 PM7:07 AMNov 47:07 AMNov 4Mar 12DSTMar 12DSTDSTNov 5DSTNov 5daynightnightnightnight
The solar day over the course of the year 2017. 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 transitions to and from daylight saving time are indicated by the 'DST' labels.

Humidity

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.

Jamestown experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.2 months, from May 18 to September 23, during which time the comfort level is muggy, oppressive, or miserable at least 20% of the time. The muggiest day of the year is July 25, with muggy conditions 81% of the time.

The least muggy day of the year is January 30, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels in Jamestownmuggy0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 300%Jan 300%81%Jul 2581%Jul 25May 1820%May 1820%Sep 2321%Sep 2321%miserablemiserableoppressiveoppressivemuggymuggycomfortablecomfortabledrydry
The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

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 Jamestown experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.6 months, from October 27 to May 14, with average wind speeds of more than 3.4 miles per hour. The windiest day of the year is February 25, with an average hourly wind speed of 4.3 miles per hour.

The calmer time of year lasts for 5.4 months, from May 14 to October 27. The calmest day of the year is August 1, with an average hourly wind speed of 2.5 miles per hour.

Average Wind Speed

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

The predominant average hourly wind direction in Jamestown varies throughout the year.

The wind is most often from the west for 1.6 months, from January 5 to February 22 and for 1.8 months, from June 23 to August 16, with a peak percentage of 40% on July 13. The wind is most often from the south for 4.0 months, from February 22 to June 23 and for 4.6 months, from August 16 to January 5, with a peak percentage of 38% on May 24.

Wind Direction

Wind Direction in JamestownWSWS0%20%40%60%80%100%JanFebMarAprMayJunJulAugSepOctNovDecwestsoutheastnorth
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Solar Energy

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 experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 4.5 months, from April 19 to September 4, with an average daily incident shortwave energy per square meter above 5.7 kWh. The brightest day of the year is June 22, with an average of 6.6 kWh.

The darker period of the year lasts for 3.0 months, from November 9 to February 9, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest day of the year is December 24, with an average of 2.1 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in Jamestownbrightdarkdark0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJanFebMarAprMayJunJulAugSepOctNovDecJun 226.6 kWhJun 226.6 kWhDec 242.1 kWhDec 242.1 kWhApr 195.7 kWhApr 195.7 kWhSep 45.7 kWhSep 45.7 kWhNov 93.0 kWhNov 93.0 kWhFeb 93.0 kWhFeb 93.0 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.

Topography

For the purposes of this report, the geographical coordinates of Jamestown are 36.985 deg latitude, -85.063 deg longitude, and 935 ft elevation.

The topography within 2 miles of Jamestown contains only modest variations in elevation, with a maximum elevation change of 295 feet and an average elevation above sea level of 915 feet. Within 10 miles contains only modest variations in elevation (594 feet). Within 50 miles contains significant variations in elevation (1,896 feet).

The area within 2 miles of Jamestown is covered by cropland (68%) and trees (28%), within 10 miles by cropland (53%) and trees (33%), and within 50 miles by trees (55%) and cropland (42%).

Data Sources

This report illustrates the typical weather in Jamestown, 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 Jamestown.

For each station, the records are corrected for the elevation difference between that station and Jamestown 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 Jamestown is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Jamestown and a given station.

The stations contributing to this reconstruction are: Wayne County Airport (74%, 23 kilometers, southeast); Stuart Powell Field (14%, 71 kilometers, north); and Glasgow Municipal Airport (12%, 79 kilometers, west).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.