Rancho Penasquitos weather in December

In December, Rancho Penasquitos sees average daytime highs of 64°F and overnight lows near 44°F, with 2.3 in of rain across 5.4 wet days and about 9.9 hours of daylight. It is the 12th-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 64°F through the month. The sky is clear or mostly clear about 51% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 hours at the start of December to 9 h 54 min by month's end. Set against the rest of the year, December is Rancho Penasquitos's 9th-clearest and 5th-windiest month. For the whole year in context, see Rancho Penasquitos's year-round climate.

Daytime high
64°
12th warmest
Overnight low
44°
2nd coldest
Rainfall
2.3 in
5.4 wet days
Daylight
9 h 48 min
6:50 AM – 4:40 PM
Cloud cover
42%
9th clearest
Wind
4 mph
5th windiest
Solar energy
3.13 kWh/m²
Travel score
6.7
out of 10

Rancho Penasquitos is human settlement in San Diego, California, United States of America.

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 64°F through the month.

A typical December day in Rancho Penasquitos reaches about 64°F in the afternoon and slips back to 44°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 56°F and 73°F. Set against its neighbours, December runs about 6°F cooler than November and on par with January.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16646
26646
36646
46546
56546
66546
76545
86545
96545
106445
116445
126445
136445
146444
156444
166444
176444
186444
196344
206344
216344
226344
236344
246343
256343
266343
276343
286343
296343
306344
316444

Rancho Penasquitos weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan64° / 44°2.96.210.16.7
Feb64° / 46°3.87.410.86.3
Mar66° / 48°2.56.411.76.8
Apr69° / 51°1.24.412.87.6
May72° / 55°0.62.613.78.3
Jun77° / 59°0.10.614.19.2
Jul81° / 64°0.11148.6
Aug83° / 65°0.10.513.27.9
Sep82° / 63°0.2112.28.3
Oct77° / 57°0.82.811.28.6
Nov70° / 50°1.33.710.37.9
Dec64° / 44°2.35.49.96.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 51% 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 36%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16634
26634
36634
46535
56535
66535
76535
86535
96436
106436
116337
126436
136436
146436
156436
166436
176436
186337
196337
206436
216436
226337
236337
246337
256238
266337
276238
286238
296139
306139
316139

Chance of precipitation in December

Any precipitation

Rancho Penasquitos gets around 2.3 in of rain over 5.4 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 18% and peaks near 20% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
116
217
317
417
517
617
717
817
917
1018
1118
1218
1318
1418
1518
1618
1718
1818
1918
2018
2118
2218
2318
2418
2518
2619
2719
2819
2919
3020
3120

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
8982
9982
10991
11991
12991
13991
14991
15991
16991
17991
18991
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
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 10 hours at the start of December to 9 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:39 AM to 6:56 AM, and sunset from 4:38 PM to 4:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.06:394:38
210.06:404:38
310.06:404:38
49.96:414:38
59.96:424:38
69.96:434:38
79.96:434:38
89.96:444:38
99.96:454:38
109.96:464:38
119.96:464:38
129.96:474:39
139.96:484:39
149.86:484:39
159.86:494:39
169.86:504:40
179.86:504:40
189.86:514:40
199.86:514:41
209.86:524:41
219.86:524:42
229.86:534:42
239.86:534:43
249.86:544:43
259.86:544:44
269.86:544:44
279.86:554:45
289.86:554:45
299.86:554:46
309.86:564:47
319.96:564:47

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.13 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.13 kWh/m² to a high of 8.17 kWh/m² in June across the year — December's 3.13 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.3Moderate
23.2Moderate
33.2Moderate
43.2Moderate
53.2Moderate
63.1Moderate
73.1Moderate
83.1Moderate
93.1Moderate
103.1Moderate
113.1Moderate
123.1Moderate
133.0Moderate
143.0Moderate
153.0Moderate
163.0Moderate
173.0Moderate
183.0Moderate
193.0Moderate
203.1Moderate
213.1Moderate
223.1Moderate
233.1Moderate
243.1Moderate
253.1Moderate
263.1Moderate
273.1Moderate
283.2Moderate
293.2Moderate
303.2Moderate
313.2Moderate
Planning a trip in December

Is December a good time to visit Rancho Penasquitos?

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

6.7
Sightseeing
10th-best month of the year
2.2
Beach & pool
11th-best month of the year

December is a reasonable time to visit Rancho Penasquitos for sightseeing.

What to pack for Rancho Penasquitos in December

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

In December, Rancho Penasquitos sees daytime highs around 64°F and nights near 44°F. Worth packing: a warm layer. About 5 days see rain.

a warm layer

Sea temperature near Rancho Penasquitos in December

The nearest coast averages about 61°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 16 mi away) is warmest in August at about 70°F and coldest in February near 59°F.

It's comfortable for a long swim from Jul 8 to Oct 6 — about 3 months when the water holds above 68°F.

60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°F)Comfort
Jan60Cool
Feb59Cool
Mar60Cool
Apr61Cool
May64Cool
Jun66Cool
Jul69Refreshing
Aug70Refreshing
Sep70Refreshing
Oct67Cool
Nov64Cool
Dec61Cool

UV index in Rancho Penasquitos in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Rancho Penasquitos peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 11Dec 17UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5High
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Rancho Penasquitos 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 Rancho Penasquitos is worst in September — around 26 µg/m³ PM2.5 (moderate), about 3.4× the cleanest month (May, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateSep 1625 µg/m³May 168 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb12Moderate
Mar12Moderate
Apr11Good
May8Good
Jun11Good
Jul11Good
Aug15Moderate
Sep26Moderate
Oct14Moderate
Nov12Moderate
Dec16Moderate
Location & terrain

Where is Rancho Penasquitos?

Rancho Penasquitos sits at 33.0°N, 117.1°W, 600 ft above sea level, in United States. The nearest listed city is Mira Mesa, 3.7 mi away.

Topography around Rancho Penasquitos

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

Within 2 miles, the terrain around Rancho Penasquitos has significant variations in elevation — a maximum elevation change of 1,302 ft around an average of 617 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,835 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,450 ft.

The land around Rancho Penasquitos is covered by artificial surfaces (45%), trees (25%) and shrubs (22%) within 2 miles, artificial surfaces (29%), trees (26%) and shrubs (24%) within 10 miles, and shrubs (27%) and water (27%) within 50 miles.

2 miles
1,302 ft
10 miles
2,835 ft
50 miles
6,450 ft
treesshrubsgrasslandartificial surfacesbare terrainwater
December weather nearby: Mira Mesa 3.7 mi · Poway 4.3 mi · Escondido 11 mi · Encinitas 12 mi · Santee 12 mi · La Jolla 12 mi · San Marcos 13 mi · Lakeside 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 Rancho Penasquitos (32.9595°, -117.1153°, elevation 600 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).