Jamestown weather in December

In December, Jamestown sees average daytime highs of 21°C and overnight lows near 21°C, with 1 mm of rain across 0 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 21°C through the month. The sky is clear or mostly clear about 36% of the time in December, and the air most often feels humid.

Daylight stretches from about 12 h 54 min at the start of December to 12 h 54 min by month's end. Set against the rest of the year, December is Jamestown's 5th-clearest and 10th-windiest month. For the whole year in context, see Jamestown's year-round climate.

Daytime high
21°
7th warmest
Overnight low
21°
6th coldest
Rainfall
1 mm
0 wet days
Daylight
12 h 54 min
5:51 AM – 6:47 PM
Cloud cover
48%
5th clearest
Wind
24 km/h
10th windiest
Solar energy
6.95 kWh/m²
Travel score
8.2
out of 10

Jamestown is capital of Saint Helena.

Density
177/km²
people per km²
Founded
1659

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 21°C through the month.

A typical December day in Jamestown reaches about 21°C in the afternoon and slips back to 21°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 22°C. Set against its neighbours, December runs about 1°C warmer than November and about 1°C cooler than January.

15°18°20°23°25°151015202531
Avg high (°C)Avg low (°C)
12120
22120
32120
42120
52120
62120
72120
82120
92120
102120
112120
122120
132121
142121
152121
162121
172121
182121
192121
202221
212221
222221
232221
242221
252221
262221
272221
282221
292221
302221
312221

Jamestown weather by month

How December compares with the rest of the year at a glance. December is the 7th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan23° / 22°20.412.88.6
Feb24° / 23°30.612.58.8
Mar24° / 24°51.412.18.7
Apr24° / 23°30.611.78.7
May23° / 22°41.111.38.3
Jun22° / 21°51.111.17.9
Jul21° / 20°30.511.17.7
Aug20° / 19°20.311.57.4
Sep20° / 19°10.111.97.3
Oct20° / 19°10.112.47.4
Nov20° / 20°1012.77.7
Dec21° / 21°1012.98.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 41% of December, with mostly cloudy or overcast conditions the remaining 23%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16733
26832
36931
47030
57129
67129
77228
87228
97327
107426
117426
127426
137624
147624
157624
167723
177822
187822
197921
207921
218020
228020
238119
248218
258218
268218
278218
288218
298218
308218
318317

Chance of precipitation in December

Any precipitation

Jamestown gets around 1 mm of rain over 0 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 0% and peaks near 0% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the humid band about 75% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)
126722
224733
323743
422744
521754
620755
719756
818766
917767
1017767
1116768
1216759
1315769
14157510
15147610
16137611
17127612
18127612
19117613
20107614
2197714
2297615
2387616
2477518
2567519
2667420
2757322
2847224
2947125
3037027
3136829

Wind in December

Winds average 24 km/h in December.

Across December, daily wind ranges from about 24 km/h on the calmest days to 25 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202531
Wind speed (km/h)Feels
125breezy
225breezy
325breezy
425breezy
525breezy
624breezy
724breezy
824breezy
924breezy
1024breezy
1124breezy
1224breezy
1324breezy
1424breezy
1524breezy
1624breezy
1724breezy
1824breezy
1924breezy
2024breezy
2124breezy
2224breezy
2324breezy
2424breezy
2524breezy
2624breezy
2724breezy
2824breezy
2924breezy
3024breezy
3124breezy

Sunrise & sunset in December

DaylightNight

Daylight runs from about 12 h 54 min at the start of December to 12 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over December. Sunrise moves from 5:46 AM to 5:58 AM, and sunset from 6:39 PM to 6:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:466:39
212.95:466:40
312.95:476:40
412.95:476:41
512.95:476:41
612.95:476:42
712.95:486:42
812.95:486:43
912.95:486:44
1012.95:496:44
1112.95:496:45
1212.95:496:45
1312.95:506:46
1412.95:506:46
1512.95:506:47
1612.95:516:47
1712.95:516:48
1812.95:526:48
1912.95:526:49
2012.95:526:49
2112.95:536:50
2212.95:536:50
2312.95:546:51
2412.95:546:51
2512.95:556:52
2612.95:556:52
2712.95:566:52
2812.95:566:53
2912.95:576:53
3012.95:576:54
3112.95:586:54

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.95 kWh/m².

For context, solar energy here swings from a low near 3.89 kWh/m² to a high of 7.11 kWh/m² in January across the year — December's 6.95 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
16.8Intense
26.8Intense
36.8Intense
46.8Intense
56.8Intense
66.9Intense
76.9Intense
86.9Intense
96.9Intense
106.9Intense
116.9Intense
126.9Intense
136.9Intense
146.9Intense
156.9Intense
167.0Intense
177.0Intense
187.0Intense
197.0Intense
207.0Intense
217.0Intense
227.0Intense
237.0Intense
247.0Intense
257.0Intense
267.0Intense
277.0Intense
287.0Intense
297.0Intense
307.0Intense
317.0Intense
Planning a trip in December

Is December a good time to visit Jamestown?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

8.2
Sightseeing
6th-best month of the year
5.2
Beach & pool
7th-best month of the year

December is one of the better times to visit Jamestown for general sightseeing.

What to pack for Jamestown in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Jamestown sees daytime highs around 21°C and nights near 21°C. Pack sun protection. Worth having: a windbreaker.

sun protectiona windbreaker

Sea temperature near Jamestown in December

The nearest coast averages about 22°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in March at about 25°C and coldest in October near 20°C.

The water stays above 20°C all year — warm enough for a swim any month.

18°20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan23Refreshing
Feb24Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug21Refreshing
Sep20Refreshing
Oct20Refreshing
Nov21Refreshing
Dec22Refreshing

UV index in Jamestown in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Jamestown peaks around January 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 8 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeJan 20UV 14Jun 21UV 8
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar13Extreme
Apr11Extreme
May9Very high
Jun8Very high
Jul8Very high
Aug8Very high
Sep10Very high
Oct11Extreme
Nov13Extreme
Dec12Extreme
Location & terrain

Where is Jamestown?

Jamestown sits at 15.9°S, 5.7°W, 10 m above sea level, in Saint Helena. The nearest listed city is Tômbua, 1,878 km away.

Topography around Jamestown

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Jamestown.

Within 3 km, the terrain around Jamestown has significant variations in elevation — a maximum elevation change of 581 m around an average of 155 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 795 m; within 80 km, large variations in elevation — a maximum elevation change of 766 m.

The land around Jamestown is covered by water (44%) and shrubs (27%) within 3 km, water (85%) within 16 km, and water (97%) within 80 km.

3 km
581 m
16 km
795 m
80 km
766 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Tômbua 1,878 km · Mossamedes 1,915 km · Virei 1,997 km · Camucuio 2,045 km · Dombe Grande 2,053 km · Lubango 2,062 km · Baía Farta 2,071 km · Navegantes 2,092 km

Saint Helena travel facts

Power plugs
Type G
230 V · 50 Hz

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Jamestown (-15.9249°, -5.7182°, elevation 10 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).