※ Download: Key west hourly weather
The average water temperature experiences some seasonal variation over the course of the year. Over the course of the year, the temperature typically varies from 65°F to 89°F and is rarely below 56°F or above 91°F. Mariners and motorists can expect brief moderate downpours and reduced visibilities below 2 NM, wind gusts up to 30 knots, and occasional lightning with the strongest convection. The chance of wet days in Key West varies significantly throughout the year.
Key West experiences extreme seasonal variation in the perceived humidity. In Key West, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year. The time of year with warmer water lasts for 3.
- 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.
Average Weather in Key West Florida, United States In Key West, the summers are long, hot, oppressive, wet, and mostly cloudy and the winters are short, comfortable, humid, windy, and mostly clear. Over the course of the year, the temperature typically varies from 65°F to 89°F and is rarely below 56°F or above 91°F. The hot season lasts for 4. The hottest day of the year is August 7, with an average high of 89°F and low of 81°F. The cool season lasts for 3. The coldest day of the year is January 18, with an average low of 65°F and high of 74°F. In Key West, 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 Key West begins around October 20 and lasts for 7. On March 6, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 73% of the time, and overcast or mostly cloudy 27% of the time. The cloudier part of the year begins around May 23 and lasts for 4. On June 20, the cloudiest day of the year, the sky is overcast or mostly cloudy 70% of the time, and clear, mostly clear, or partly cloudy 30% of the time. A wet day is one with at least 0. The chance of wet days in Key West varies significantly throughout the year. The wetter season lasts 4. The chance of a wet day peaks at 59% on September 16. The drier season lasts 7. The smallest chance of a wet day is 12% on March 20. 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 59% on September 16. 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. Key West experiences extreme seasonal variation in monthly rainfall. Rain falls throughout the year in Key West. The most rain falls during the 31 days centered around September 10, with an average total accumulation of 6. The least rain falls around March 29, with an average total accumulation of 1. 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 6:35 AM on November 4, and the latest sunrise is 1 hour, 4 minutes later at 7:40 AM on March 11. The earliest sunset is at 5:37 PM on November 29, and the latest sunset is 2 hours, 42 minutes later at 8:20 PM on July 3. Daylight saving time DST is observed in Key West during 2018, starting in the spring on March 11, lasting 7. The solar day over the course of the year 2018. 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. Key West experiences extreme seasonal variation in the perceived humidity. The muggier period of the year lasts for 8. The muggiest day of the year is August 7, with muggy conditions 100% of the time. The least muggy day of the year is January 30, with muggy conditions 42% of the time. 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 Key West experiences significant seasonal variation over the course of the year. The windier part of the year lasts for 6. The windiest day of the year is November 7, with an average hourly wind speed of 14. The calmer time of year lasts for 5. The calmest day of the year is July 29, with an average hourly wind speed of 9. 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. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions northeast, southeast, southwest, and northwest. Water Temperature Key West is located near a large body of water e. This section reports on the wide-area average surface temperature of that water. The average water temperature experiences some seasonal variation over the course of the year. The time of year with warmer water lasts for 3. The day of the year with the warmest water is August 13, with an average temperature of 86°F. The time of year with cooler water lasts for 3. The day of the year with the coolest water is February 3, with an average temperature of 73°F. To characterize how pleasant the weather is in Key West 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 Key West for general outdoor tourist activities is from mid November to mid April, with a peak score in the second week of February. The tourism score filled area , and its constituents: the temperature score red line , the cloud cover score blue line , and the precipitation score green line. Based on this score, the best times of year to visit Key West for hot-weather activities are from mid March to mid May and from late October to late November, with a peak score in the last week of April. Methodology 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. 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. Temperatures in Key West are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year. 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. 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 2. The brightest day of the year is April 28, with an average of 6. The darker period of the year lasts for 2. The darkest day of the year is December 23, with an average of 3. For the purposes of this report, the geographical coordinates of Key West are 24. The topography within 2 miles of Key West is essentially flat, with a maximum elevation change of 10 feet and an average elevation above sea level of 2 foot. Within 10 miles is also essentially flat 10 feet. Within 50 miles is also essentially flat 16 feet. The area within 2 miles of Key West is covered by water 59% and artificial surfaces 37% , within 10 miles by water 95% , and within 50 miles by water 99%. Data Sources This report illustrates the typical weather in Key West, 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 is only a single weather station, , in our network suitable to be used as a proxy for the historical temperature and dew point records of Key West. At a distance of 3 kilometers from Key West, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records. The station records are corrected for the elevation difference between the station and Key West according to the , and by the relative change present in the between the two locations. Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis. Other Data All data relating to the Sun's position e. All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's. 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 , published by the Food and Agriculture Organization of the United Nations. Elevation data comes from the , published by NASA's Jet Propulsion Laboratory. Names, locations, and time zones of places and some airports come from the. Time zones for aiports and weather stations are provided by. Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC. 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.
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. The day of the year with the warmest water is August 13, with an average temperature of 86°F. The most rain falls during the 31 days centered around September 10, with an average total accumulation of 6. In Key West, the average percentage of the sky key west hourly weather by clouds experiences significant seasonal variation over the course of the year. At a distance of 3 kilometers from Key West, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records. 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.
