Seaside weather in December

In December, Seaside sees average daytime highs of 56°F and overnight lows near 43°F, with 3.8 in of rain across 8.5 wet days and about 9.5 hours of daylight. It is the 11th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 56°F through the month. The sky is clear or mostly clear about 39% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 42 min at the start of December to 9 h 30 min by month's end. Set against the rest of the year, December is Seaside's 9th-clearest and 5th-windiest month. For the whole year in context, see Seaside's year-round climate.

Daytime high
56°
11th warmest
Overnight low
43°
1st coldest
Rainfall
3.8 in
8.5 wet days
Daylight
9 h 30 min
7:18 AM – 4:49 PM
Cloud cover
53%
9th clearest
Wind
6 mph
5th windiest
Solar energy
2.53 kWh/m²
Travel score
4.0
out of 10

Seaside is city in Monterey County, California, United States.

Density
1,360/km²
people per km²
Founded
1954

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 56°F through the month.

A typical December day in Seaside reaches about 56°F in the afternoon and slips back to 43°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 50°F and 62°F. Set against its neighbours, December runs about 5°F cooler than November and on par with January.

30°40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15844
25744
35744
45744
55744
65744
75744
85744
95644
105644
115644
125644
135643
145643
155643
165643
175643
185643
195643
205643
215643
225643
235643
245543
255543
265543
275543
285543
295543
305543
315643

Seaside weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan56° / 44°4.29.19.84.0
Feb57° / 44°4.29.610.64.0
Mar58° / 45°3.39.111.74.5
Apr59° / 46°1.55.512.95.3
May62° / 48°0.62.913.96.6
Jun66° / 50°0.10.614.58.1
Jul70° / 53°0.00.214.28.7
Aug71° / 54°0.10.213.48.8
Sep70° / 53°0.10.612.28.7
Oct67° / 51°0.92.511.17.9
Nov61° / 46°1.95.8105.7
Dec56° / 43°3.88.59.54.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 48%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15545
25446
35347
45347
55248
65248
75149
85149
95149
105050
115050
125050
135149
145149
155248
165248
175248
185347
195347
205347
215347
225347
235248
245248
255248
265149
275149
285050
295050
304951
314852

Chance of precipitation in December

Any precipitation

Seaside gets around 3.8 in of rain over 8.5 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 27% and peaks near 28% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
126
226
327
427
527
628
728
828
928
1028
1128
1228
1328
1428
1528
1627
1727
1827
1927
2027
2127
2227
2327
2427
2527
2628
2728
2828
2928
3028
3128

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1982
2982
3982
4982
5982
6982
7982
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991
31991

Wind in December

Winds average 6 mph in December.

Across December, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 42 min at the start of December to 9 h 30 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 7:07 AM to 7:25 AM, and sunset from 4:48 PM to 4:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.77:074:48
29.77:084:47
39.67:094:47
49.67:094:47
59.67:104:47
69.67:114:47
79.67:124:47
89.67:134:47
99.67:134:47
109.67:144:48
119.57:154:48
129.57:164:48
139.57:164:48
149.57:174:48
159.57:184:49
169.57:184:49
179.57:194:49
189.57:194:50
199.57:204:50
209.57:214:50
219.57:214:51
229.57:224:51
239.57:224:52
249.57:224:52
259.57:234:53
269.57:234:53
279.57:244:54
289.57:244:54
299.57:244:55
309.57:244:56
319.57:254:56

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.53 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.53 kWh/m² to a high of 8.03 kWh/m² in June across the year — December's 2.53 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.6Moderate
22.6Moderate
32.6Moderate
42.6Moderate
52.5Moderate
62.5Moderate
72.5Moderate
82.5Moderate
92.5Moderate
102.5Moderate
112.5Moderate
122.5Moderate
132.5Moderate
142.5Moderate
152.5Moderate
162.5Moderate
172.5Moderate
182.5Moderate
192.5Moderate
202.5Moderate
212.5Moderate
222.5Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.6Moderate
292.6Moderate
302.6Moderate
312.6Moderate
Planning a trip in December

Hazard calendar for Seaside

In seasonPeak

In December, Seaside sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Seaside's rainy season runs December–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Seaside?

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

4.0
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a reasonable time to visit Seaside for sightseeing.

What to pack for Seaside in December

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

In December, Seaside sees daytime highs around 56°F and nights near 43°F. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Seaside in December

The nearest coast averages about 55°F 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 September at about 58°F and coldest in April near 54°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

52°54°56°58°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan55Bracing
Feb55Bracing
Mar55Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul57Bracing
Aug58Bracing
Sep58Bracing
Oct58Bracing
Nov57Bracing
Dec55Bracing

UV index in Seaside in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Seaside peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 13UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in Seaside in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Seaside is worst in August — around 22 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (June, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1920 µg/m³Jun 135 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar8Good
Apr7Good
May6Good
Jun5Good
Jul8Good
Aug22Moderate
Sep15Moderate
Oct12Moderate
Nov8Good
Dec7Good
Location & terrain

Where is Seaside?

Seaside sits at 36.6°N, 121.9°W, 23 ft above sea level, in United States. The nearest listed city is Monterey, 2.5 mi away.

Topography around Seaside

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Seaside.

Within 2 miles, the terrain around Seaside has only modest variations in elevation — a maximum elevation change of 417 ft around an average of 89 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,218 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,883 ft.

The land around Seaside is covered by artificial surfaces (39%) and water (36%) within 2 miles, water (39%) and trees (31%) within 10 miles, and water (33%), trees (28%) and grassland (27%) within 50 miles.

2 miles
417 ft
10 miles
2,218 ft
50 miles
5,883 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Monterey 2.5 mi · Pacific Grove 3.7 mi · Marina 5.6 mi · Salinas 12 mi · Prunedale 15 mi · Watsonville 21 mi · Big Sur 24 mi · Live Oak 27 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 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 Seaside (36.6111°, -121.8516°, elevation 23 ft), 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).