Big Sur weather in September

In September, Big Sur sees average daytime highs of 67°F and overnight lows near 55°F, with 0.1 in of rain across 0.6 wet days and about 12.2 hours of daylight. It is the 2nd-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 67°F through the month. The sky is clear or mostly clear about 86% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Big Sur's 2nd-clearest and 10th-windiest month. For the whole year in context, see Big Sur's year-round climate.

Daytime high
67°
2nd warmest
Overnight low
55°
11th coldest
Rainfall
0.1 in
0.6 wet days
Daylight
12 h 12 min
5:55 AM – 6:08 PM
Cloud cover
17%
2nd clearest
Wind
8 mph
10th windiest
Solar energy
6.15 kWh/m²
Travel score
8.4
out of 10

Big Sur is region in Monterey County, California, United States.

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 67°F through the month.

A typical September day in Big Sur reaches about 67°F in the afternoon and slips back to 55°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 75°F. Set against its neighbours, September runs on par with August and about 3°F warmer than October.

50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
16855
26855
36855
46855
56855
66855
76755
86755
96755
106755
116755
126755
136755
146755
156755
166755
176755
186755
196755
206755
216755
226755
236755
246755
256755
266755
276755
286755
296754
306654

Big Sur weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan55° / 46°5.19.39.83.7
Feb55° / 46°4.89.310.63.6
Mar56° / 46°3.48.311.74.1
Apr57° / 47°1.75.712.94.7
May59° / 49°0.72.613.95.8
Jun63° / 51°0.10.414.47.4
Jul66° / 54°0.00.114.28.3
Aug67° / 55°0.10.313.48.5
Sep67° / 55°0.10.612.28.4
Oct65° / 53°0.92.411.17.6
Nov59° / 49°2.26.110.15.3
Dec55° / 46°4.59.29.63.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 86% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 7% of September, with mostly cloudy or overcast conditions the remaining 7%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1964
2964
3964
4973
5973
6973
7973
8964
9964
10964
11964
12964
13955
14955
15955
16946
17946
18937
19928
20928
21928
22919
23919
249010
259010
268911
278911
288911
298812
308812

Chance of precipitation in September

Any precipitation

Big Sur gets around 0.1 in of rain over 0.6 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 2% and peaks near 4% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
11
21
31
41
52
62
72
82
92
102
112
122
132
142
152
162
172
182
192
202
212
222
232
242
253
263
273
283
293
304

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 90% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
187121
287121
387121
488111
588111
688111
789101
889101
989101
1089101
1189101
1289101
1389101
1489101
1589101
1690100
1790100
1889110
1989110
2089110
2190100
2290100
2390100
2490100
259190
269190
279280
289280
299370
309370

Wind in September

Winds average 8 mph in September.

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

051015151015202530
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
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 5:43 AM to 6:06 AM, and sunset from 6:31 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:436:31
212.85:436:30
312.75:446:28
412.75:456:27
512.75:466:25
612.65:476:24
712.65:486:22
812.55:486:21
912.55:496:19
1012.55:506:18
1112.45:516:16
1212.45:526:15
1312.35:526:13
1412.35:536:11
1512.35:546:10
1612.25:556:08
1712.25:566:07
1812.15:566:05
1912.15:576:04
2012.15:586:02
2112.05:596:01
2212.06:005:59
2312.06:005:57
2411.96:015:56
2511.96:025:54
2611.86:035:53
2711.86:045:51
2811.86:055:50
2911.76:055:48
3011.76:065:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.15 kWh/m².

For context, solar energy here swings from a low near 2.59 kWh/m² to a high of 8.18 kWh/m² in June across the year — September's 6.15 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.8Intense
26.8Intense
36.7Intense
46.7Intense
56.6Intense
66.6Intense
76.5Intense
86.5Intense
96.5Intense
106.4Intense
116.4Intense
126.3Intense
136.3Intense
146.2Intense
156.2Intense
166.1Intense
176.1Intense
186.0Intense
196.0Bright
205.9Bright
215.9Bright
225.8Bright
235.8Bright
245.7Bright
255.7Bright
265.6Bright
275.6Bright
285.5Bright
295.5Bright
305.4Bright
Planning a trip in September

Hazard calendar for Big Sur

In seasonPeak

None of Big Sur's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Big Sur'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 September a good time to visit Big Sur?

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

8.4
Sightseeing
2nd-best month of the year
4.0
Beach & pool
2nd-best month of the year

September is one of the better times to visit Big Sur for general sightseeing.

What to pack for Big Sur in September

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

In September, Big Sur sees daytime highs around 67°F and nights near 55°F. Pack sun protection.

sun protection

Sea temperature near Big Sur in September

The nearest coast averages about 59°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 8 mi away) is warmest in September 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
Jan55Bracing
Feb55Bracing
Mar55Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul57Bracing
Aug58Bracing
Sep59Bracing
Oct58Bracing
Nov57Bracing
Dec56Bracing

UV index in Big Sur in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Big Sur peaks around June 22 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 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 22UV 11Dec 12UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun11Extreme
Jul10Extreme
Aug10Very high
Sep7High
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Big Sur in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Big Sur is worst in September — around 27 µg/m³ PM2.5 (moderate), about 7.0× the cleanest month (December, 4 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1027 µg/m³Dec 174 µg/m³
PM2.5 (µg/m³)Level
Jan4Good
Feb5Good
Mar5Good
Apr5Good
May5Good
Jun5Good
Jul16Moderate
Aug25Moderate
Sep27Moderate
Oct6Good
Nov4Good
Dec4Good
Location & terrain

Where is Big Sur?

Big Sur sits at 36.3°N, 121.8°W, 0 ft above sea level, in United States. The nearest listed city is Monterey, 24 mi away.

Topography around Big Sur

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

Within 2 miles, the terrain around Big Sur has large variations in elevation — a maximum elevation change of 3,455 ft around an average of 1,145 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 4,918 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,758 ft.

The land around Big Sur is covered by trees (77%) within 2 miles, water (45%) and trees (43%) within 10 miles, and water (40%), grassland (27%) and trees (22%) within 50 miles.

2 miles
3,455 ft
10 miles
4,918 ft
50 miles
5,758 ft
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Monterey 24 mi · Seaside 24 mi · Pacific Grove 25 mi · Marina 29 mi · Soledad 29 mi · Salinas 29 mi · Greenfield 32 mi · Prunedale 36 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 Big Sur (36.2702°, -121.8075°, elevation 0 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).