Oakley weather in January

In January, Oakley sees average daytime highs of 57°F and overnight lows near 43°F, with 3.7 in of rain across 9 wet days and about 9.7 hours of daylight. It is the 11th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 56°F in the first days to 59°F by the end. The sky is clear or mostly clear about 30% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of January to 10 hours by month's end. Set against the rest of the year, January is Oakley's 12th-clearest and 12th-windiest month. For the whole year in context, see Oakley's year-round climate.

Daytime high
57°
11th warmest
Overnight low
43°
1st coldest
Rainfall
3.7 in
9 wet days
Daylight
9 h 36 min
7:27 AM – 5:05 PM
Cloud cover
61%
12th clearest
Wind
4 mph
12th windiest
Solar energy
2.3 kWh/m²
Travel score
4.2
out of 10

Oakley is city in Contra Costa County, California, United States.

Density
950/km²
people per km²
Founded
1999

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 56°F in the first days to 59°F by the end.

A typical January day in Oakley reaches about 57°F in the afternoon and slips back to 43°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 52°F and 63°F. Set against its neighbours, January runs on par with December and about 4°F cooler than February.

30°40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15642
25642
35642
45642
55642
65642
75642
85642
95642
105642
115642
125742
135742
145742
155743
165743
175743
185743
195843
205843
215843
225843
235843
245843
255843
265943
275943
285944
295944
306044
316044

Oakley weather by month

How January compares with the rest of the year at a glance. January is the 11th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan57° / 43°3.799.74.2
Feb61° / 45°3.58.810.55.2
Mar66° / 48°2.78.311.76.4
Apr70° / 50°1.24.7137.6
May76° / 54°0.63148.5
Jun82° / 57°0.10.714.68.3
Jul84° / 59°0.00.214.47.7
Aug84° / 59°0.10.213.57.7
Sep82° / 58°0.00.312.38.3
Oct76° / 54°0.92.8118.6
Nov65° / 47°1.85.49.96.6
Dec57° / 43°3.48.49.44.3

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 13% of January, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24258
34159
44159
54159
64159
74159
84159
94258
104159
114258
124258
134357
144357
154258
164357
174357
184456
194456
204456
214456
224456
234456
244456
254555
264456
274456
284357
294555
304555
314555

Chance of precipitation in January

Any precipitation

Oakley gets around 3.7 in of rain over 9 wet days in January, the wettest month. 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
227
327
427
527
627
727
828
928
1028
1128
1228
1329
1429
1529
1630
1730
1831
1931
2031
2131
2231
2331
2431
2530
2630
2730
2829
2929
3028
3128

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January 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
161000
171000
181000
191000
201000
211000
221000
231000
241000
25991
26991
27991
28991
29991
30991
31991

Wind in January

Winds average 4 mph in January, the calmest month.

Across January, 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 January

DaylightNight

Daylight runs from about 9 h 24 min at the start of January to 10 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over January. Sunrise moves from 7:28 AM to 7:19 AM, and sunset from 4:52 PM to 5:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:284:52
29.47:284:53
39.47:284:54
49.47:284:54
59.47:284:55
69.57:284:56
79.57:284:57
89.57:284:58
99.57:284:59
109.57:285:00
119.57:285:00
129.67:285:01
139.67:285:02
149.67:285:03
159.67:275:04
169.67:275:05
179.77:275:06
189.77:265:07
199.77:265:08
209.77:265:09
219.87:255:10
229.87:255:11
239.87:245:12
249.87:245:13
259.97:235:14
269.97:235:16
279.97:225:17
289.97:215:18
2910.07:215:19
3010.07:205:20
3110.07:195:21

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.3 kWh/m².

For context, solar energy here swings from a low near 2.16 kWh/m² to a high of 8.13 kWh/m² in June across the year — January's 2.3 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.2Moderate
22.2Moderate
32.2Moderate
42.2Moderate
52.2Moderate
62.2Moderate
72.2Moderate
82.2Moderate
92.2Moderate
102.2Moderate
112.2Moderate
122.2Moderate
132.2Moderate
142.3Moderate
152.3Moderate
162.3Moderate
172.3Moderate
182.4Moderate
192.4Moderate
202.4Moderate
212.4Moderate
222.5Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.6Moderate
272.6Moderate
282.6Moderate
292.7Moderate
302.7Moderate
312.8Moderate
Planning a trip in January

Is January a good time to visit Oakley?

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

4.2
Sightseeing
12th-best month of the year
0.0
Beach & pool
12th-best month of the year

January is a reasonable time to visit Oakley for sightseeing.

What to pack for Oakley in January

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

In January, Oakley sees daytime highs around 57°F and nights near 43°F. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

UV index in Oakley in January

LowModerateHighVery highExtreme

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

Under clear skies, the midday UV index in Oakley peaks around June 22 at about 10 (very high) — 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 highHighModerateJun 22UV 10Dec 15UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr6High
May8Very high
Jun10Very high
Jul10Very high
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Low

Air quality in Oakley in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Oakley is worst in August — around 27 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (June, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 2126 µg/m³Jun 138 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb14Moderate
Mar15Moderate
Apr12Good
May9Good
Jun8Good
Jul11Good
Aug27Moderate
Sep23Moderate
Oct17Moderate
Nov19Moderate
Dec14Moderate
Location & terrain

Where is Oakley?

Oakley sits at 38.0°N, 121.7°W, 20 ft above sea level, in United States. The nearest listed city is Brentwood, 4.3 mi away.

Topography around Oakley

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

Within 2 miles, the terrain around Oakley has only modest variations in elevation — a maximum elevation change of 125 ft around an average of 30 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,857 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,452 ft.

The land around Oakley is covered by artificial surfaces (38%) within 2 miles, grassland (35%) and cropland (26%) within 10 miles, and grassland (35%) and trees (21%) within 50 miles.

2 miles
125 ft
10 miles
1,857 ft
50 miles
4,452 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
January weather nearby: Brentwood 4.3 mi · Antioch 5.0 mi · Pittsburg 9.3 mi · Bay Point 14 mi · Concord 17 mi · Pleasant Hill 19 mi · Danville 20 mi · Walnut Creek 21 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 Oakley (37.9974°, -121.7125°, elevation 20 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. 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).