Arroyo Grande weather in January

In January, Arroyo Grande sees average daytime highs of 59°F and overnight lows near 47°F, with 3.8 in of rain across 7.2 wet days and about 9.9 hours of daylight. It is the 10th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 59°F through the month. The sky is clear or mostly clear about 48% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 42 min at the start of January to 10 h 12 min by month's end. Set against the rest of the year, January is Arroyo Grande's 11th-clearest and 5th-windiest month. For the whole year in context, see Arroyo Grande's year-round climate.

Daytime high
59°
10th warmest
Overnight low
47°
2nd coldest
Rainfall
3.8 in
7.2 wet days
Daylight
9 h 54 min
7:15 AM – 5:08 PM
Cloud cover
47%
11th clearest
Wind
7 mph
5th windiest
Solar energy
3.03 kWh/m²
Travel score
5.1
out of 10

Arroyo Grande is city in San Luis Obispo County, California, United States.

Density
1,199/km²
people per km²
Founded
1862

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 59°F through the month.

A typical January day in Arroyo Grande reaches about 59°F in the afternoon and slips back to 47°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 53°F and 66°F. Set against its neighbours, January runs on par with December and on par with February.

40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15947
25947
35947
45947
55947
65947
75947
85947
95947
105947
115947
125947
135947
145947
155947
165947
175947
185947
195947
205947
215947
225947
235947
245947
255947
265947
275947
285947
295947
305947
316047

Arroyo Grande weather by month

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

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan59° / 47°3.87.29.95.1
Feb59° / 48°3.67.810.74.9
Mar60° / 49°2.86.311.75.5
Apr62° / 50°1.03.312.96.4
May64° / 53°0.41.613.87.3
Jun66° / 56°0.10.414.38.2
Jul69° / 59°0.00.214.18.5
Aug70° / 59°0.00.113.38.8
Sep70° / 59°0.00.412.28.7
Oct68° / 56°0.81.811.18.3
Nov64° / 51°1.43.710.26.9
Dec59° / 47°2.86.19.75.2

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 12% of January, with mostly cloudy or overcast conditions the remaining 40%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35743
45743
55644
65644
75743
85743
95842
105842
115941
125941
135941
145941
155941
166040
176139
186139
196139
206139
216139
226139
236139
246238
256238
266238
276238
286238
296238
306238
316238

Chance of precipitation in January

Any precipitation

Arroyo Grande gets around 3.8 in of rain over 7.2 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 23% and peaks near 24% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
124
224
324
424
524
624
724
824
923
1023
1123
1223
1323
1423
1523
1623
1723
1823
1924
2023
2123
2223
2323
2423
2523
2622
2722
2822
2922
3022
3122

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 (%)
1982
2982
3982
4982
5982
6982
7982
8982
9982
10982
11982
12991
13991
14991
15991
16991
17991
18991
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
30991
31991

Wind in January

Winds average 7 mph in January.

Across January, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
137light breeze
147light breeze
157light breeze
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287light breeze
297light breeze
307light breeze
317light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 42 min at the start of January to 10 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 30 minutes over January. Sunrise moves from 7:15 AM to 7:09 AM, and sunset from 4:56 PM to 5:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.77:154:56
29.77:164:56
39.77:164:57
49.77:164:58
59.77:164:59
69.77:164:59
79.77:165:00
89.77:165:01
99.87:165:02
109.87:165:03
119.87:165:04
129.87:165:04
139.87:165:05
149.87:165:06
159.97:165:07
169.97:155:08
179.97:155:09
189.97:155:10
199.97:155:11
2010.07:145:12
2110.07:145:13
2210.07:135:14
2310.07:135:15
2410.07:135:16
2510.17:125:17
2610.17:125:18
2710.17:115:19
2810.17:115:20
2910.27:105:21
3010.27:095:22
3110.27:095:23

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 3.03 kWh/m².

For context, solar energy here swings from a low near 2.84 kWh/m² to a high of 8.24 kWh/m² in June across the year — January's 3.03 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
12.9Moderate
22.9Moderate
32.9Moderate
42.9Moderate
52.9Moderate
62.9Moderate
72.9Moderate
82.9Moderate
92.9Moderate
102.9Moderate
112.9Moderate
123.0Moderate
133.0Moderate
143.0Moderate
153.0Moderate
163.0Moderate
173.0Moderate
183.1Moderate
193.1Moderate
203.1Moderate
213.1Moderate
223.2Moderate
233.2Moderate
243.2Moderate
253.3Moderate
263.3Moderate
273.3Moderate
283.4Moderate
293.4Moderate
303.4Moderate
313.5Moderate
Planning a trip in January

Is January a good time to visit Arroyo Grande?

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

5.1
Sightseeing
11th-best month of the year
0.1
Beach & pool
11th-best month of the year

January is a reasonable time to visit Arroyo Grande for sightseeing.

What to pack for Arroyo Grande in January

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

In January, Arroyo Grande sees daytime highs around 59°F and nights near 47°F. Worth packing: a warm layer. About 7 days see rain.

a warm layer

Sea temperature near Arroyo Grande in January

The nearest coast averages about 56°F in January — 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 60°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°62°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan56Bracing
Feb56Bracing
Mar55Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul58Bracing
Aug59Cool
Sep60Cool
Oct60Cool
Nov58Bracing
Dec57Bracing

UV index in Arroyo Grande in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Arroyo Grande peaks around June 21 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 21UV 11Dec 15UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7Very high
May8Very high
Jun11Extreme
Jul10Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Arroyo Grande 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 Arroyo Grande is worst in August — around 19 µg/m³ PM2.5 (moderate), about 4.5× the cleanest month (June, 4 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 2218 µg/m³Jun 124 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb6Good
Mar7Good
Apr6Good
May5Good
Jun4Good
Jul7Good
Aug19Moderate
Sep17Moderate
Oct7Good
Nov6Good
Dec5Good
Location & terrain

Where is Arroyo Grande?

Arroyo Grande sits at 35.1°N, 120.6°W, 118 ft above sea level, in United States. The nearest listed city is Nipomo, 8.1 mi away.

Topography around Arroyo Grande

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

Within 2 miles, the terrain around Arroyo Grande has only modest variations in elevation — a maximum elevation change of 486 ft around an average of 151 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,808 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,715 ft.

The land around Arroyo Grande is covered by artificial surfaces (48%) and grassland (21%) within 2 miles, grassland (32%), water (25%) and trees (23%) within 10 miles, and grassland (47%) and water (27%) within 50 miles.

2 miles
486 ft
10 miles
2,808 ft
50 miles
5,715 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Nipomo 8.1 mi · San Luis Obispo 12 mi · Santa Maria 14 mi · Orcutt 19 mi · Atascadero 26 mi · Lompoc 34 mi · Paso Robles 35 mi · Isla Vista 64 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 Arroyo Grande (35.1186°, -120.5907°, elevation 118 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).