Saint John weather in December

In December, Saint John sees average daytime highs of 2°C and overnight lows near -4°C, with 137 mm of precipitation across 13.1 wet days and about 8.6 hours of daylight. It is the 10th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 4°C in the first days to -0°C by the end. The sky is clear or mostly clear about 24% of the time in December, and the air most often feels dry.

Daylight stretches from about 8 h 48 min at the start of December to 8 h 36 min by month's end. Set against the rest of the year, December is Saint John's 7th-clearest and 1st-windiest month. For the whole year in context, see Saint John's year-round climate.

Daytime high
10th warmest
Overnight low
-4°
3rd coldest
Precipitation
137 mm
13.1 wet days
Daylight
8 h 36 min
8:04 AM – 4:37 PM
Cloud cover
67%
7th clearest
Wind
22 km/h
1st windiest
Solar energy
1.28 kWh/m²
Travel score
0.0
out of 10

Saint John is city in New Brunswick, Canada.

Air quality
Excellent
PM2.5 5 µg/m³ · 2019
Density
227/km²
people per km²
Founded
1604

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 4°C in the first days to -0°C by the end.

A typical December day in Saint John reaches about 2°C in the afternoon and slips back to -4°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between -5°C and 8°C. Set against its neighbours, December runs about 5°C cooler than November and about 4°C warmer than January.

-20°-10°10°151015202531
Avg high (°C)Avg low (°C)
14-1
24-1
34-2
44-2
54-2
63-2
73-3
83-3
93-3
103-3
112-4
122-4
132-4
142-4
152-4
162-4
172-5
181-5
191-5
201-5
211-5
221-5
231-6
241-6
250-6
260-6
270-6
280-7
290-7
300-7
31-1-7

How December really feels in Saint John

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
31
21 feel bitter (≤ -10°C)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Saint John weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -9°11211.68.48.90.0
Feb-1° / -8°9510.38.210.10.0
Mar / -4°11211.47.211.60.0
Apr / 10512.33.413.20.5
May11° / 10412.30.214.62.4
Jun15° / 11°10812.1015.44.3
Jul18° / 14°9111015.15.6
Aug19° / 14°819.3013.96.1
Sep16° / 12°10810012.35.1
Oct12° / 13310.90.210.73.1
Nov / 12811.82.39.30.8
Dec / -4°13713.16.98.60.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 62%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53862
63862
73862
83763
93763
103862
113862
123862
133862
143862
153862
163862
173763
183763
193763
203763
213862
223862
233862
243862
253961
263961
274060
283862
293961
303961
314060

Chance of precipitation in December

Any precipitationSnow

Saint John gets around 137 mm of rain and snow over 13.1 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 42% and peaks near 42% on the wettest days, and about 7 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
14217
24217
34218
44218
54118
64119
74119
84119
94119
104119
114119
124119
134119
144119
154119
164119
174120
184220
194221
204222
214222
224223
234224
244225
254226
264226
274227
284228
294229
304229
314230

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 22 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 21 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
121breezy
221breezy
321breezy
421breezy
521breezy
621breezy
721breezy
821breezy
921breezy
1021breezy
1122breezy
1222breezy
1322breezy
1422breezy
1522breezy
1622breezy
1722breezy
1822breezy
1922breezy
2022breezy
2122breezy
2222breezy
2322breezy
2422breezy
2522breezy
2622breezy
2722breezy
2822breezy
2922breezy
3022breezy
3122breezy

Sunrise & sunset in December

DaylightNight

Daylight runs from about 8 h 48 min at the start of December to 8 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:50 AM to 8:10 AM, and sunset from 4:38 PM to 4:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.87:504:38
28.87:514:38
38.87:524:37
48.77:534:37
58.77:544:37
68.77:554:37
78.77:564:37
88.77:574:37
98.67:584:37
108.67:594:36
118.68:004:37
128.68:014:37
138.68:014:37
148.68:024:37
158.68:034:37
168.68:044:37
178.68:044:37
188.58:054:38
198.58:054:38
208.58:064:39
218.58:074:39
228.58:074:39
238.58:074:40
248.58:084:40
258.58:084:41
268.58:094:42
278.68:094:42
288.68:094:43
298.68:094:44
308.68:104:44
318.68:104:45

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.28 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.28 kWh/m² to a high of 5.62 kWh/m² in June across the year — December's 1.28 kWh/m² sits near the bottom.

00.511.52151015202531
Solar energy (kWh/m²)Level
11.4Dim
21.3Dim
31.3Dim
41.3Dim
51.3Dim
61.3Dim
71.3Dim
81.3Dim
91.3Dim
101.3Dim
111.3Dim
121.3Dim
131.3Dim
141.3Dim
151.3Dim
161.3Dim
171.3Dim
181.3Dim
191.3Dim
201.3Dim
211.3Dim
221.3Dim
231.3Dim
241.3Dim
251.3Dim
261.3Dim
271.3Dim
281.3Dim
291.4Dim
301.4Dim
311.4Dim
Planning a trip in December

Is December a good time to visit Saint John?

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

0.0
Sightseeing
9th-best month of the year
0.0
Beach & pool
7th-best month of the year

December is a weaker month for outdoor sightseeing in Saint John.

What to pack for Saint John in December

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

In December, Saint John sees daytime highs around 2°C and nights near -4°C. Pack a warm layer and a heavy coat. Worth having: rain gear and a windbreaker. About 13 days see rain.

a warm layera heavy coatrain geara windbreaker

Sea temperature near Saint John in December

The nearest coast averages about 7°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 17 km away) is warmest in August at about 14°C and coldest in March near 2°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

0°5°10°15°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan5Bracing
Feb3Bracing
Mar2Bracing
Apr3Bracing
May6Bracing
Jun9Bracing
Jul13Bracing
Aug14Bracing
Sep13Bracing
Oct12Bracing
Nov10Bracing
Dec7Bracing

UV index in Saint John in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Saint John peaks around July 11 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 11UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May7High
Jun7Very high
Jul7Very high
Aug6High
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Saint John?

Saint John sits at 45.3°N, 66.1°W, 30 m above sea level, in Canada. The nearest listed city is Saint John West, 2.0 km away.

Topography around Saint John

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

Within 3 km, the terrain around Saint John has only modest variations in elevation — a maximum elevation change of 95 m around an average of 16 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 234 m; within 80 km, significant variations in elevation — a maximum elevation change of 449 m.

The land around Saint John is covered by water (38%), artificial surfaces (29%) and trees (21%) within 3 km, trees (52%) and water (38%) within 16 km, and trees (49%) and water (45%) within 80 km.

3 km
95 m
16 km
234 m
80 km
449 m
treesgrasslandartificial surfacesbare terrainwaterwetland
December weather nearby: Saint John West 2.0 km · Quispamsis 19 km · Fredericton 89 km · Fredericton Northside 91 km · Riverview 130 km · Lutes Mountain 131 km · Moncton 134 km · Dieppe 139 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 2%

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 Saint John (45.2708°, -66.0562°, elevation 30 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).