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Average Weather at Annapolis, United States Naval Academy Maryland, United States

At Annapolis, United States Naval Academy, the summers are warm and muggy; the winters are very cold, wet, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 29°F to 85°F and is rarely below 17°F or above 91°F.

Climate Summary

very coldcoldcoolwarmcoolcoldJanFebMarAprMayJunJulAugSepOctNovDec65%65%48%48%clearovercastprecipitation: 3.6 inprecipitation: 3.6 in2.7 in2.7 inmuggy: 73%muggy: 73%0%0%drydrytourism score: 7.1tourism score: 7.10.20.2
Click on each chart for more information.

Based on the tourism score, the best times of year to visit Annapolis, United States Naval Academy for warm-weather activities are for the entire month of June and from mid August to early October.

Temperature

The warm season lasts for 3.7 months, from May 31 to September 19, with an average daily high temperature above 76°F. The hottest day of the year is July 21, with an average high of 85°F and low of 72°F.

The cold season lasts for 3.2 months, from December 3 to March 11, with an average daily high temperature below 50°F. The coldest day of the year is January 30, with an average low of 29°F and high of 41°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 at Annapolis, United States Naval AcademyJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMvery coldcoldcoldcoolcoolcomfortablewarmwarmvery coldfreezing
The average hourly temperature, color coded into bands: 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 shaded overlays indicate night and civil twilight.

Pohang, South Korea (7,005 miles away) is the far-away foreign place with temperatures most similar to Annapolis, United States Naval Academy (view comparison).

Clouds

At Annapolis, United States Naval Academy, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year at Annapolis, United States Naval Academy begins around July 5 and lasts for 4.4 months, ending around November 18. On October 12, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 65% of the time, and overcast or mostly cloudy 35% of the time.

The cloudier part of the year begins around November 18 and lasts for 7.6 months, ending around July 5. On January 5, 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

Cloud Cover Categories at Annapolis, United States Naval AcademyclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Oct 1265%Oct 1265%Jan 548%Jan 548%Jul 556%Jul 556%Nov 1856%Nov 1856%clearmostly clearpartly cloudymostly cloudyovercast
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 at Annapolis, United States Naval Academy varies throughout the year.

The wetter season lasts 4.7 months, from April 2 to August 24, with a greater than 30% chance of a given day being a wet day. The chance of a wet day peaks at 38% on August 4.

The drier season lasts 7.3 months, from August 24 to April 2. The smallest chance of a wet day is 21% on January 28.

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 38% on August 4.

Daily Chance of Precipitation

Daily Chance of Precipitation at Annapolis, United States Naval AcademywetdrydryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Aug 438%Aug 438%Jan 2821%Jan 2821%Jan 123%Jan 123%Apr 230%Apr 230%rainsnow
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. Annapolis, United States Naval Academy experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year at Annapolis, United States Naval Academy. The most rain falls during the 31 days centered around September 27, with an average total accumulation of 3.6 inches.

The least rain falls around January 31, with an average total accumulation of 2.1 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. Annapolis, United States Naval Academy experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 3.9 months, from November 28 to March 24, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around February 6, with an average total liquid-equivalent accumulation of 0.6 inches.

The snowless period of the year lasts for 8.1 months, from March 24 to November 28. The least snow falls around July 21, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall at Annapolis, United States Naval AcademysnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.5 in1.0 in1.5 in2.0 in2.5 in3.0 in3.5 in4.0 inFeb 60.6 inFeb 60.6 inJul 210.0 inJul 210.0 inNov 280.1 inNov 280.1 inMar 240.1 inMar 240.1 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 at Annapolis, United States Naval Academy varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 26 minutes of daylight; the longest day is June 21, with 14 hours, 54 minutes of daylight.

Hours of Daylight and Twilight

Hours of Daylight and Twilight at Annapolis, United States Naval AcademyJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 7 minMar 2012 hr, 7 minMar 2014 hr, 54 minJun 2114 hr, 54 minJun 2112 hr, 9 minSep 2212 hr, 9 minSep 229 hr, 26 minDec 219 hr, 26 minDec 21nightnightday
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 5:39 AM on June 14, and the latest sunrise is 1 hour, 57 minutes later at 7:36 AM on November 4. The earliest sunset is at 4:43 PM on December 7, and the latest sunset is 3 hours, 52 minutes later at 8:35 PM on June 27.

Daylight saving time (DST) is observed at Annapolis, United States Naval Academy 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 at Annapolis, United States Naval AcademyJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:39 AMJun 145:39 AM8:35 PMJun 278:35 PMJun 27Dec 74:43 PMDec 74:43 PM7:36 AMNov 47:36 AMNov 4Mar 12DSTMar 12DSTDSTNov 5DSTNov 5daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
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.

Annapolis, United States Naval Academy experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.4 months, from May 21 to October 1, during which time the comfort level is muggy, oppressive, or miserable at least 18% of the time. The muggiest day of the year is August 2, with muggy conditions 73% of the time.

The least muggy day of the year is February 11, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels at Annapolis, United States Naval AcademymuggyJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Feb 110%Feb 110%Aug 273%Aug 273%May 2118%May 2118%Oct 118%Oct 118%oppressiveoppressivemuggymuggydrydrymiserablemiserablecomfortablecomfortable
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 at Annapolis, United States Naval Academy experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.0 months, from October 10 to May 9, with average wind speeds of more than 9.1 miles per hour. The windiest day of the year is February 26, with an average hourly wind speed of 11.3 miles per hour.

The calmer time of year lasts for 5.0 months, from May 9 to October 10. The calmest day of the year is August 1, with an average hourly wind speed of 6.9 miles per hour.

Average Wind Speed

Average Wind Speed at Annapolis, United States Naval AcademywindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mphFeb 2611.3 mphFeb 2611.3 mphAug 16.9 mphAug 16.9 mphOct 109.1 mphOct 109.1 mphMay 99.1 mphMay 99.1 mph
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 at Annapolis, United States Naval Academy varies throughout the year.

The wind is most often from the north for 4.3 weeks, from March 1 to March 31, with a peak percentage of 32% on March 10. The wind is most often from the west for 3.3 weeks, from March 31 to April 23; for 2.3 weeks, from July 3 to July 19; and for 4.5 months, from October 18 to March 1, with a peak percentage of 35% on July 6. The wind is most often from the south for 2.4 months, from April 23 to July 3 and for 3.0 months, from July 19 to October 18, with a peak percentage of 36% on August 2.

Wind Direction

Wind Direction at Annapolis, United States Naval AcademyWNWSWSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
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).

Water Temperature

Annapolis, United States Naval Academy is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences extreme seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.3 months, from June 23 to October 2, with an average temperature above 69°F. The day of the year with the warmest water is August 12, with an average temperature of 77°F.

The time of year with cooler water lasts for 3.6 months, from December 19 to April 6, with an average temperature below 44°F. The day of the year with the coolest water is February 10, with an average temperature of 36°F.

Average Water Temperature

Average Water Temperature at Annapolis, United States Naval AcademywarmcoolJanFebMarAprMayJunJulAugSepOctNovDec30°F40°F50°F60°F70°F80°F90°FAug 1277°FAug 1277°F36°FFeb 1036°FFeb 10Jun 2369°FJun 2369°FOct 269°FOct 269°FDec 1944°FDec 1944°FApr 644°FApr 644°F
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Best Time of Year to Visit

To characterize how pleasant the weather is at Annapolis, United States Naval Academy 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 times of year to visit Annapolis, United States Naval Academy for general outdoor tourist activities are for the entire month of June and from mid August to early October, with a peak score in the first week of September.

Tourism Score

Tourism Score at Annapolis, United States Naval Academybest timeJanFebMarAprMayJunJulAugSepOctNovDec02468107.17.10.20.26.46.45.95.9 precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
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).

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 Annapolis, United States Naval Academy for hot-weather activities is from late June to early September, with a peak score in the third week of July.

Beach/Pool Score

Beach/Pool Score at Annapolis, United States Naval Academybest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.66.60.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturebeach/pool score
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

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 0.04 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.

Growing Season

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 at Annapolis, United States Naval Academy typically lasts for 8.0 months (245 days), from around March 25 to around November 25, rarely starting before March 6 or after April 12, and rarely ending before November 5 or after December 16.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season at Annapolis, United States Naval Academygrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Mar 2550%Mar 2550%Nov 2550%Nov 2590%Apr 1290%Apr 1290%Nov 590%Nov 510%Mar 610%Mar 610%Dec 1610%Dec 160%Jan 240%Jan 24Jul 23100%Jul 23100%freezingvery coldcoldcomfortablewarmcoolhot
The percentage of time spent in various temperature bands: 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 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.

Based on growing degree days alone, the first spring blooms at Annapolis, United States Naval Academy should appear around April 1, only rarely appearing before March 16 or after April 17.

Growing Degree Days

Growing Degree Days at Annapolis, United States Naval AcademyJanFebMarAprMayJunJulAugSepOctNovDec0°F500°F1,000°F1,500°F2,000°F2,500°F3,000°F3,500°F4,000°FApr 182°FApr 182°FJun 10900°FJun 10900°FJul 161,800°FJul 161,800°FDec 314,082°FDec 314,082°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

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 3.8 months, from April 27 to August 21, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is June 23, with an average of 6.9 kWh.

The darker period of the year lasts for 3.1 months, from November 6 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 23, with an average of 2.0 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy at Annapolis, United States Naval AcademybrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJun 236.9 kWhJun 236.9 kWhDec 232.0 kWhDec 232.0 kWhApr 275.9 kWhApr 275.9 kWhAug 215.9 kWhAug 215.9 kWhNov 63.0 kWhNov 63.0 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 Annapolis, United States Naval Academy are 38.991 deg latitude, -76.483 deg longitude, and 23 ft elevation.

The topography within 2 miles of Annapolis, United States Naval Academy contains only modest variations in elevation, with a maximum elevation change of 118 feet and an average elevation above sea level of 25 feet. Within 10 miles also contains only modest variations in elevation (197 feet). Within 50 miles contains only modest variations in elevation (1,060 feet).

The area within 2 miles of Annapolis, United States Naval Academy is covered by water (33%), trees (33%), and artificial surfaces (27%), within 10 miles by water (46%) and trees (30%), and within 50 miles by trees (32%) and cropland (30%).

Data Sources

This report illustrates the typical weather at Annapolis, United States Naval Academy, 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

Annapolis, United States Naval Academy 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 Thomas Point Coast Guard Station; Baltimore-Washington International Airport; Tipton Airport; Baltimore, Inner Harbor; Martin State Airport; Washington Executive Airport/Hyde Field; College Park Airport; and Easton Airport.

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.

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.