Pleasanton weather in December

In December, Pleasanton sees average daytime highs of 56°F and overnight lows near 41°F, with 3.1 in of rain across 8.8 wet days and about 9.4 hours of daylight. It is the 12th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 58°F in the first days to 55°F by the end. The sky is clear or mostly clear about 36% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of December to 9 h 24 min by month's end. Set against the rest of the year, December is Pleasanton's 10th-clearest and 10th-windiest month. For the whole year in context, see Pleasanton's year-round climate.

Daytime high
56°
12th warmest
Overnight low
41°
1st coldest
Rainfall
3.1 in
8.8 wet days
Daylight
9 h 24 min
7:21 AM – 4:46 PM
Cloud cover
56%
10th clearest
Wind
4 mph
10th windiest
Solar energy
2.25 kWh/m²
Travel score
4.0
out of 10

Pleasanton is city in Alameda County, California, United States.

Density
1,265/km²
people per km²
Founded
1839

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 58°F in the first days to 55°F by the end.

A typical December day in Pleasanton reaches about 56°F in the afternoon and slips back to 41°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 62°F. Set against its neighbours, December runs about 7°F cooler than November and on par with January.

30°40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15842
25842
35842
45842
55842
65742
75742
85742
95742
105742
115642
125641
135641
145641
155641
165641
175641
185541
195540
205540
215540
225540
235540
245540
255540
265540
275540
285540
295540
305540
315540

Pleasanton weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan56° / 41°3.49.49.74.0
Feb59° / 43°3.38.810.54.7
Mar63° / 45°2.68.711.75.9
Apr68° / 47°1.35.212.97.2
May73° / 51°0.63148.4
Jun80° / 55°0.20.814.68.8
Jul84° / 58°0.00.214.37.8
Aug83° / 58°0.10.313.57.8
Sep81° / 56°0.10.512.38.7
Oct74° / 52°0.82.8118.6
Nov63° / 45°1.65.6106.3
Dec56° / 41°3.18.89.44.0

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 13% of December, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15149
25050
35050
44852
54951
64951
74852
84753
94951
104852
114852
124951
134951
144951
154951
164951
175050
185050
195050
205050
215050
225050
235050
244951
254951
264951
274852
284753
294753
304654
314654

Chance of precipitation in December

Any precipitation

Pleasanton gets around 3.1 in of rain over 8.8 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 29% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
127
228
328
429
530
630
731
831
931
1031
1131
1231
1331
1431
1530
1630
1729
1829
1928
2028
2127
2227
2327
2427
2526
2626
2727
2827
2927
3027
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 (%)
1991
2991
3991
4991
5991
6991
7991
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 4 mph in December.

Across December, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 36 min at the start of December to 9 h 24 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 7:10 AM to 7:28 AM, and sunset from 4:45 PM to 4:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.67:104:45
29.67:114:45
39.67:114:45
49.57:124:45
59.57:134:44
69.57:144:44
79.57:154:44
89.57:164:44
99.57:164:45
109.57:174:45
119.47:184:45
129.47:194:45
139.47:194:45
149.47:204:45
159.47:214:46
169.47:214:46
179.47:224:46
189.47:234:47
199.47:234:47
209.47:244:47
219.47:244:48
229.47:254:48
239.47:254:49
249.47:264:49
259.47:264:50
269.47:264:50
279.47:274:51
289.47:274:52
299.47:274:52
309.47:284:53
319.47:284:54

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.25 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.25 kWh/m² to a high of 8.21 kWh/m² in June across the year — December's 2.25 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.4Moderate
22.4Moderate
32.3Moderate
42.3Moderate
52.3Moderate
62.3Moderate
72.3Moderate
82.2Moderate
92.2Moderate
102.2Moderate
112.2Moderate
122.2Moderate
132.2Moderate
142.2Moderate
152.2Moderate
162.2Moderate
172.2Moderate
182.2Moderate
192.2Moderate
202.2Moderate
212.2Moderate
222.2Moderate
232.2Moderate
242.2Moderate
252.3Moderate
262.3Moderate
272.3Moderate
282.3Moderate
292.3Moderate
302.3Moderate
312.3Moderate
Planning a trip in December

Is December a good time to visit Pleasanton?

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

4.0
Sightseeing
11th-best month of the year
0.0
Beach & pool
11th-best month of the year

December is a reasonable time to visit Pleasanton for sightseeing.

What to pack for Pleasanton in December

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

In December, Pleasanton sees daytime highs around 56°F and nights near 41°F. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Pleasanton 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 at the nearest coast (about 34 mi away) is warmest in August at about 59°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
Jan54Bracing
Feb54Bracing
Mar54Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul57Bracing
Aug59Bracing
Sep59Bracing
Oct58Bracing
Nov56Bracing
Dec55Bracing

UV index in Pleasanton 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 Pleasanton peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 15UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in Pleasanton 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 Pleasanton is worst in August — around 34 µg/m³ PM2.5 (moderate), about 4.9× the cleanest month (June, 7 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 1832 µg/m³Jun 157 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun7Good
Jul9Good
Aug34Moderate
Sep16Moderate
Oct14Moderate
Nov15Moderate
Dec12Good
Location & terrain

Where is Pleasanton?

Pleasanton sits at 37.7°N, 121.9°W, 348 ft above sea level, in United States. The nearest listed city is Dublin, 4.3 mi away.

Topography around Pleasanton

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

Within 2 miles, the terrain around Pleasanton has only modest variations in elevation — a maximum elevation change of 522 ft around an average of 390 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,392 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.

The land around Pleasanton is covered by artificial surfaces (43%), trees (30%) and grassland (23%) within 2 miles, grassland (52%), trees (23%) and artificial surfaces (20%) within 10 miles, and grassland (28%) and trees (27%) within 50 miles.

2 miles
522 ft
10 miles
2,392 ft
50 miles
4,452 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Dublin 4.3 mi · Livermore 6.2 mi · Union City 9.3 mi · San Ramon 9.9 mi · Fremont 9.9 mi · Hayward 11 mi · Castro Valley 12 mi · Newark 13 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 Pleasanton (37.6624°, -121.8747°, elevation 348 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).