1. WeatherSpark.com
  2. British Indian Ocean Territory

Climate and Average Weather Year Round in British Indian Ocean Territory British Indian Ocean Territory

The climate in British Indian Ocean Territory is hot, oppressive, windy, and overcast. Over the course of the year, the temperature typically varies from 76°F to 88°F and is rarely below 74°F or above 91°F.

Based on the beach/pool score, the best time of year to visit British Indian Ocean Territory for hot-weather activities is from late May to early September.

Climate in British Indian Ocean Territory

hotwarmhotJanFebMarAprMayJunJulAugSepOctNovDecNowNow38%38%21%21%overcastprecipitation: 11.1 inprecipitation: 11.1 in2.7 in2.7 inmuggy: 100%muggy: 100%97%97%beach/pool score: 6.5beach/pool score: 6.53.93.9
British Indian Ocean Territory weather by month. Click on each chart for more information.

The temperature in British Indian Ocean Territory varies so little throughout the year that it is not entirely meaningful to discuss hot and cold seasons.

Average High and Low Temperature in British Indian Ocean Territory

Average High and Low Temperature in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FAug 1184°FAug 1184°FMar 2588°FMar 2588°F76°F76°F79°F79°FMay 287°FMay 287°FJun 2785°FJun 2785°FSep 2685°FSep 2685°F79°F79°F79°F79°F77°F77°F77°F77°FNowNow
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.
AverageJanFebMarAprMayJunJulAugSepOctNovDec
High86°F87°F88°F88°F87°F85°F84°F84°F84°F85°F87°F87°F
Temp.82°F82°F83°F83°F82°F81°F80°F80°F80°F81°F82°F82°F
Low78°F78°F79°F79°F79°F78°F77°F77°F77°F77°F78°F78°F

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 British Indian Ocean Territory

Average Hourly Temperature in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMNowNowwarmhothot
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 average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.
Map
Marker
© Esri, et al.

Compare British Indian Ocean Territory to another city:

Map

In British Indian Ocean Territory, 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 in British Indian Ocean Territory begins around April 3 and lasts for 6.1 months, ending around October 8.

The clearest month of the year in British Indian Ocean Territory is July, during which on average the sky is clear, mostly clear, or partly cloudy 37% of the time.

The cloudier part of the year begins around October 8 and lasts for 5.9 months, ending around April 3.

The cloudiest month of the year in British Indian Ocean Territory is January, during which on average the sky is overcast or mostly cloudy 79% of the time.

Cloud Cover Categories in British Indian Ocean Territory

Cloud Cover Categories in British Indian Ocean TerritoryclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Jul 3038%Jul 3038%Jan 1021%Jan 1021%Apr 329%Apr 329%Oct 830%Oct 830%NowNowmostly clearpartly cloudymostly cloudyovercastclear
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.
FractionJanFebMarAprMayJunJulAugSepOctNovDec
Cloudier79%77%72%69%65%65%63%64%68%71%71%74%
Clearer21%23%28%31%35%35%37%36%32%29%29%26%

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

The wetter season lasts 6.1 months, from September 20 to March 25, with a greater than 49% chance of a given day being a wet day. The month with the most wet days in British Indian Ocean Territory is January, with an average of 21.1 days with at least 0.04 inches of precipitation.

The drier season lasts 5.9 months, from March 25 to September 20. The month with the fewest wet days in British Indian Ocean Territory is July, with an average of 9.7 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in British Indian Ocean Territory is January, with an average of 21.1 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 70% on January 21.

Daily Chance of Precipitation in British Indian Ocean Territory

Daily Chance of Precipitation in British Indian Ocean TerritorywetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Jan 2170%Jan 2170%Jul 3128%Jul 3128%Jan 167%Jan 167%Sep 2049%Sep 2049%Mar 2549%Mar 2549%NowNowrain
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).
Days ofJanFebMarAprMayJunJulAugSepOctNovDec
Rain21.1d17.2d15.5d13.3d11.3d10.1d9.7d10.5d14.2d17.3d16.2d18.1d

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. British Indian Ocean Territory experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in British Indian Ocean Territory. The month with the most rain in British Indian Ocean Territory is January, with an average rainfall of 11.1 inches.

The month with the least rain in British Indian Ocean Territory is July, with an average rainfall of 3.0 inches.

Average Monthly Rainfall in British Indian Ocean Territory

Average Monthly Rainfall in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in5 in5 in10 in10 in15 in15 in20 in20 inJan 1511.1 inJan 1511.1 inAug 32.7 inAug 32.7 inOct 277.5 inOct 277.5 inApr 285.2 inApr 285.2 inJun 283.3 inJun 283.3 inNowNow
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 snowfall.
JanFebMarAprMayJunJulAugSepOctNovDec
Rainfall11.1″8.6″5.7″5.0″4.2″3.2″3.0″3.0″5.9″7.4″7.1″7.6″

The length of the day in British Indian Ocean Territory does not vary substantially over the course of the year, staying within 28 minutes of 12 hours throughout. In 2021, the shortest day is June 21, with 11 hours, 47 minutes of daylight; the longest day is December 21, with 12 hours, 28 minutes of daylight.

Hours of Daylight and Twilight in British Indian Ocean Territory

Hours of Daylight and Twilight in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 6 minSep 2312 hr, 6 minSep 2312 hr, 28 minDec 2112 hr, 28 minDec 2112 hr, 7 minMar 2012 hr, 7 minMar 2011 hr, 47 minJun 2111 hr, 47 minJun 21daydaynightNowNow
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.
Hours ofJanFebMarAprMayJunJulAugSepOctNovDec
Daylight12.4h12.3h12.1h12.0h11.8h11.8h11.8h11.9h12.1h12.2h12.4h12.5h

The earliest sunrise is at 6:44 AM on November 13, and the latest sunrise is 39 minutes later at 7:23 AM on July 18. The earliest sunset is at 7:03 PM on May 23, and the latest sunset is 33 minutes later at 7:36 PM on February 1.

Daylight saving time (DST) is not observed in British Indian Ocean Territory during 2021.

Sunrise & Sunset with Twilight in British Indian Ocean Territory

Sunrise & Sunset with Twilight in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMNov 136:44 AMNov 136:44 AM7:36 PMFeb 17:36 PMFeb 1May 237:03 PMMay 237:03 PM7:23 AMJul 187:23 AMJul 18daynightSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day over the course of the year 2021. 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 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 British Indian Ocean Territory

The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

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.

The perceived humidity level in British Indian Ocean Territory, 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, staying within 2% of 98% throughout.

Humidity Comfort Levels in British Indian Ocean Territory

Humidity Comfort Levels in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Jul 3197%Jul 3197%100%Nov 24100%Nov 24NowNowmiserablemiserableoppressiveoppressivemuggymuggy
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.
JanFebMarAprMayJunJulAugSepOctNovDec
Muggy days31.0d28.0d31.0d29.9d30.7d29.4d30.1d30.0d29.1d30.8d30.0d31.0d

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 British Indian Ocean Territory experiences extreme seasonal variation over the course of the year.

The windier part of the year lasts for 5.0 months, from May 23 to October 23, with average wind speeds of more than 13.1 miles per hour. The windiest month of the year in British Indian Ocean Territory is August, with an average hourly wind speed of 17.5 miles per hour.

The calmer time of year lasts for 7.0 months, from October 23 to May 23. The calmest month of the year in British Indian Ocean Territory is March, with an average hourly wind speed of 9.0 miles per hour.

Average Wind Speed in British Indian Ocean Territory

Average Wind Speed in British Indian Ocean TerritorywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mph16 mph16 mph18 mph18 mph20 mph20 mphAug 917.7 mphAug 917.7 mphApr 58.5 mphApr 58.5 mphMay 2313.1 mphMay 2313.1 mphOct 2313.1 mphOct 2313.1 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Wind Speed (mph)10.911.09.09.212.415.717.217.516.213.510.99.6

The predominant average hourly wind direction in British Indian Ocean Territory varies throughout the year.

The wind is most often from the east for 8.1 months, from April 7 to December 11, with a peak percentage of 74% on June 23. The wind is most often from the west for 3.9 months, from December 11 to April 7, with a peak percentage of 51% on January 1.

Wind Direction in British Indian Ocean Territory

Wind Direction in British Indian Ocean TerritoryWEWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwesteastnorthsouth
northeastsouthwest
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 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

British Indian Ocean Territory 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 some seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.3 months, from March 1 to May 10, with an average temperature above 84°F. The month of the year in British Indian Ocean Territory with the warmest water is April, with an average temperature of 84°F.

The time of year with cooler water lasts for 2.6 months, from July 3 to September 20, with an average temperature below 81°F. The month of the year in British Indian Ocean Territory with the coolest water is August, with an average temperature of 80°F.

Average Water Temperature in British Indian Ocean Territory

Average Water Temperature in British Indian Ocean TerritorywarmcoolJanFebMarAprMayJunJulAugSepOctNovDec78°F78°F80°F80°F82°F82°F84°F84°F86°F86°FApr 885°FApr 885°F80°FAug 1280°FAug 12Mar 184°FMar 184°FMay 1084°FMay 1084°FJul 381°FJul 381°FSep 2081°FSep 2081°FNowNow
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.
WaterJanFebMarAprMayJunJulAugSepOctNovDec
Temperature83°F83°F84°F84°F83°F82°F81°F80°F81°F82°F83°F83°F

To characterize how pleasant the weather is in British Indian Ocean Territory 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 British Indian Ocean Territory for general outdoor tourist activities is from early July to early September, with a peak score in the first week of August.

Tourism Score in British Indian Ocean Territory

Tourism Score in British Indian Ocean Territorybest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810105.25.22.42.4NowNowprecipitationprecipitationcloudscloudstemperaturetemperature tourism 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 British Indian Ocean Territory for hot-weather activities is from late May to early September, with a peak score in the first week of August.

Beach/Pool Score in British Indian Ocean Territory

Beach/Pool Score in British Indian Ocean Territorybest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810106.56.53.93.9NowNowprecipitationprecipitationcloudscloudstemperaturetemperaturebeach/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.

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).

Temperatures in British Indian Ocean Territory 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.

Time Spent in Various Temperature Bands and the Growing Season in British Indian Ocean Territory

Time Spent in Various Temperature Bands and the Growing Season in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%100%Jan 1100%Jan 1100%Jul 3100%Jul 3NowNowwarmhot
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 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.

Growing Degree Days in British Indian Ocean Territory

Growing Degree Days in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F2,000°F2,000°F4,000°F4,000°F6,000°F6,000°F8,000°F8,000°F10,000°F10,000°FJul 490°FJul 490°FAug 301,800°FAug 301,800°FJun 3011,398°FJun 3011,398°FNowNow
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

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 per square meter does not vary significantly over the course of the year, remaining within 0.5 kilowatt-hours of 5.0 kilowatt-hours throughout.

Average Daily Incident Shortwave Solar Energy in British Indian Ocean Territory

Average Daily Incident Shortwave Solar Energy in British Indian Ocean TerritoryJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWhNov 15.5 kWhNov 15.5 kWhJun 304.6 kWhJun 304.6 kWhAug 195.3 kWhAug 195.3 kWhDec 125.3 kWhDec 125.3 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Solar Energy (kWh)4.84.95.15.05.04.74.85.35.45.45.55.2

For the purposes of this report, the geographical coordinates of British Indian Ocean Territory are -6.000 deg latitude, 72.000 deg longitude, and 0 ft elevation.

The topography within 2 miles of British Indian Ocean Territory is essentially flat, with a maximum elevation change of 0 feet and an average elevation above sea level of 0 feet. Within 10 miles is also essentially flat (0 feet). Within 50 miles is also essentially flat (0 feet).

The area within 2 miles of British Indian Ocean Territory is covered by water (100%), within 10 miles by water (100%), and within 50 miles by water (100%).

This report illustrates the typical weather in British Indian Ocean Territory, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

The details of the data sources used for this report can be found on the Diego Garcia page.

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.

Other Locations

Places

There are no places in this location for which we have data.

Airports