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December Weather in Grahamstown South Africa

Daily high temperatures increase by 4°F, from 74°F to 77°F, rarely falling below 66°F or exceeding 87°F.

Daily low temperatures increase by 3°F, from 55°F to 58°F, rarely falling below 49°F or exceeding 63°F.

For reference, on January 27, the hottest day of the year, temperatures in Grahamstown typically range from 60°F to 79°F, while on July 10, the coldest day of the year, they range from 44°F to 65°F.

Average High and Low Temperature in December in Grahamstown

Average High and Low Temperature in December in GrahamstownDec112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313145°F45°F50°F50°F55°F55°F60°F60°F65°F65°F70°F70°F75°F75°F80°F80°F85°F85°F90°F90°FNovJanDec 174°FDec 174°F55°F55°FDec 3177°FDec 3177°F58°F58°FDec 1175°FDec 1175°F56°F56°FDec 2176°FDec 2176°F57°F57°F
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 hourly average temperatures for the quarter of the year centered on December. The horizontal axis is the day, 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 December in Grahamstown

Average Hourly Temperature in December in GrahamstownDec112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 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 AMNovJancoldcoolcoolcomfortablewarm
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.

Summerland, California, United States (10,513 miles away) is the far-away foreign place with temperatures most similar to Grahamstown (view comparison).

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The month of December in Grahamstown experiences decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 32% to 22%.

The clearest day of the month is December 31, with clear, mostly clear, or partly cloudy conditions 78% of the time.

For reference, on October 21, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 39%, while on February 11, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 82%.

Cloud Cover Categories in December in Grahamstown

Cloud Cover Categories in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%NovJanDec 168%Dec 168%Dec 3178%Dec 3178%Dec 1171%Dec 1171%Dec 2175%Dec 2175%clearmostly clearpartly cloudymostly cloudyovercast
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.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Grahamstown, the chance of a wet day over the course of December is essentially constant, remaining around 27% throughout.

For reference, the year's highest daily chance of a wet day is 32% on February 25, and its lowest chance is 6% on July 3.

Probability of Precipitation in December in Grahamstown

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 month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during December in Grahamstown is gradually decreasing, starting the month at 2.5 inches, when it rarely exceeds 5.6 inches or falls below 0.5 inches, and ending the month at 2.2 inches, when it rarely exceeds 4.8 inches or falls below 0.5 inches.

The lowest average 31-day accumulation is 2.2 inches on December 18.

Average Monthly Rainfall in December in Grahamstown

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.

Over the course of December in Grahamstown, the length of the day is essentially constant. The shortest day of the month is December 1, with 14 hours, 12 minutes of daylight and the longest day is December 21, with 14 hours, 22 minutes of daylight.

Hours of Daylight and Twilight in December in Grahamstown

Hours of Daylight and Twilight in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hrNovJanDec 2114 hr, 22 minDec 2114 hr, 22 mindaydaydaydaynightDec 114 hr, 12 minDec 114 hr, 12 min
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 of the month in Grahamstown is 4:57 AM on December 5 and the latest sunrise is 10 minutes later at 5:07 AM on December 31.

The earliest sunset is 7:09 PM on December 1 and the latest sunset is 18 minutes later at 7:26 PM on December 31.

Daylight saving time is not observed in Grahamstown during 2024.

For reference, on December 21, the longest day of the year, the Sun rises at 5:01 AM and sets 14 hours, 22 minutes later, at 7:23 PM, while on June 20, the shortest day of the year, it rises at 7:17 AM and sets 9 hours, 57 minutes later, at 5:13 PM.

Sunrise & Sunset with Twilight in December in Grahamstown

Sunrise & Sunset with Twilight in December in GrahamstownDec112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMNovJan4:57 AM4:57 AMDec 57:12 PMDec 57:12 PM5:07 AM5:07 AMDec 317:26 PMDec 317:26 PM5:01 AM5:01 AMDec 217:23 PMDec 217:23 PMSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of December. 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 the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in December in Grahamstown

Solar Elevation and Azimuth in December in GrahamstownDec112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 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 AMNovJan00101020202030304040505050606070708000010102020303030404050506060607070
northeastsouthwest
Solar elevation and azimuth over the course of December 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for December 2024. 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.

Moon Rise, Set & Phases in December in Grahamstown

Moon Rise, Set & Phases in December in GrahamstownDec112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMNovJanNov 12:48 PMNov 12:48 PMNov 1511:29 PMNov 1511:29 PMDec 18:22 AMDec 18:22 AMDec 1511:02 AMDec 1511:02 AMDec 3112:28 AMDec 3112:28 AMJan 1412:28 AMJan 1412:28 AMJan 292:37 PMJan 292:37 PM4:54 AM4:54 AM6:50 PM6:50 PM6:43 PM6:43 PM5:01 AM5:01 AM4:37 AM4:37 AM7:43 PM7:43 PM6:46 PM6:46 PM4:30 AM4:30 AM5:08 AM5:08 AM8:20 PM8:20 PM7:31 PM7:31 PM5:25 AM5:25 AM5:04 AM5:04 AM7:39 PM7:39 PM
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.
Dec 2024IlluminationMoonriseMoonsetMoonriseMeridian PassingDistance
1
0%4:37 AMESE7:43 PMWSW-12:08 PMN245,937 mi
2
1%5:23 AMSE8:42 PMSW-1:02 PMN243,881 mi
3
5%6:17 AMSE9:37 PMSW-1:58 PMN241,759 mi
4
11%7:18 AMESE10:24 PMWSW-2:54 PMN239,616 mi
5
19%8:24 AMESE11:06 PMWSW-3:48 PMN237,474 mi
6
28%9:31 AMESE11:41 PMWSW-4:40 PMN235,349 mi
7
39%10:38 AMESE--5:29 PMN233,272 mi
8
50%-12:13 AMWSW11:44 AME6:16 PMN231,301 mi
9
62%-12:42 AMW12:51 PME7:02 PMN229,539 mi
10
73%-1:11 AMW1:58 PME7:50 PMN228,130 mi
11
83%-1:41 AMW3:07 PMENE8:40 PMN227,244 mi
12
91%-2:13 AMWNW4:19 PMENE9:35 PMN227,051 mi
13
97%-2:51 AMWNW5:33 PMENE10:34 PMN227,682 mi
14
100%-3:36 AMWNW6:46 PMENE11:37 PMN229,189 mi
15
100%-4:30 AMNW7:53 PMNE--
16
100%-5:31 AMNW8:52 PMENE12:42 AMN231,512 mi
17
97%-6:37 AMWNW9:41 PMENE1:45 AMN234,480 mi
18
92%-7:44 AMWNW10:20 PMENE2:43 AMN237,836 mi
19
85%-8:49 AMWNW10:53 PMENE3:35 AMN241,284 mi
20
76%-9:51 AMWNW11:21 PMENE4:22 AMN244,531 mi
21
67%-10:49 AMW11:46 PME5:05 AMN247,325 mi
22
57%-11:45 AMW-5:45 AMN249,467 mi
23
50%12:10 AME12:40 PMW-6:23 AMN250,823 mi
24
38%12:33 AME1:35 PMW-7:02 AMN251,332 mi
25
29%12:58 AMESE2:31 PMWSW-7:42 AMN251,000 mi
26
21%1:25 AMESE3:29 PMWSW-8:24 AMN249,898 mi
27
13%1:56 AMESE4:30 PMWSW-9:09 AMN248,155 mi
28
7%2:32 AMESE5:31 PMWSW-9:59 AMN245,938 mi
29
3%3:16 AMESE6:32 PMSW-10:52 AMN243,444 mi
30
0%4:08 AMSE7:29 PMSW-11:49 AMN240,874 mi
31
0%5:08 AMSE8:20 PMWSW-12:46 PMN238,412 mi

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 chance that a given day will be muggy in Grahamstown is increasing during December, rising from 2% to 8% over the course of the month.

For reference, on February 12, the muggiest day of the year, there are muggy conditions 15% of the time, while on April 30, the least muggy day of the year, there are muggy conditions 0% of the time.

Humidity Comfort Levels in December in Grahamstown

Humidity Comfort Levels in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%NovJanDec 12%Dec 12%Dec 318%Dec 318%Dec 113%Dec 113%Dec 215%Dec 215%muggymuggyhumidhumidcomfortablecomfortabledrydry
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.

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 Grahamstown is essentially constant during December, remaining within 0.1 miles per hour of 10.9 miles per hour throughout.

For reference, on June 26, the windiest day of the year, the daily average wind speed is 11.5 miles per hour, while on March 28, the calmest day of the year, the daily average wind speed is 9.5 miles per hour.

Average Wind Speed in December in Grahamstown

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

The hourly average wind direction in Grahamstown throughout December is predominantly from the east, with a peak proportion of 40% on December 11.

Wind Direction in December in Grahamstown

Wind Direction in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%20%80%40%60%60%40%80%20%100%0%NovJanwestsoutheastnorth
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).

Grahamstown 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 surface water temperature in Grahamstown is gradually increasing during December, rising by 2°F, from 69°F to 71°F, over the course of the month.

Average Water Temperature in December in Grahamstown

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

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 Grahamstown 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 December in Grahamstown

Time Spent in Various Temperature Bands and the Growing Season in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%NovJan100%Dec 16100%Dec 16coldcoolcomfortablewarmhot
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.

The average accumulated growing degree days in Grahamstown are rapidly increasing during December, increasing by 463°F, from 1,243°F to 1,706°F, over the course of the month.

Growing Degree Days in December in Grahamstown

Growing Degree Days in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031311,200°F1,200°F1,300°F1,300°F1,400°F1,400°F1,500°F1,500°F1,600°F1,600°F1,700°F1,700°F1,800°F1,800°FNovJanDec 11,243°FDec 11,243°FDec 311,706°FDec 311,706°FDec 111,386°FDec 111,386°FDec 211,541°FDec 211,541°F
The average growing degree days accumulated over the course of December, 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 in Grahamstown is essentially constant during December, remaining within 0.2 kWh of 7.8 kWh throughout.

The highest average daily incident shortwave solar energy during December is 8.0 kWh on December 22.

Average Daily Incident Shortwave Solar Energy in December in Grahamstown

Average Daily Incident Shortwave Solar Energy in December in GrahamstownDec11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWh10 kWh10 kWhNovJanDec 228.0 kWhDec 228.0 kWhDec 17.6 kWhDec 17.6 kWhDec 117.8 kWhDec 117.8 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.

For the purposes of this report, the geographical coordinates of Grahamstown are -33.304 deg latitude, 26.533 deg longitude, and 1,808 ft elevation.

The topography within 2 miles of Grahamstown contains significant variations in elevation, with a maximum elevation change of 741 feet and an average elevation above sea level of 1,955 feet. Within 10 miles contains significant variations in elevation (2,267 feet). Within 50 miles contains large variations in elevation (4,849 feet).

The area within 2 miles of Grahamstown is covered by artificial surfaces (50%), grassland (28%), and shrubs (22%), within 10 miles by shrubs (68%) and grassland (25%), and within 50 miles by shrubs (43%) and water (26%).

This report illustrates the typical weather in Grahamstown, 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 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Grahamstown.

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

The stations contributing to this reconstruction are:

To get a sense of how much these sources agree with each other, you can view a comparison of Grahamstown and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , 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 airports and weather stations are provided by AskGeo.com .

Maps are © OpenStreetMap contributors.

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.

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