South Yuba City weather in September

In September, South Yuba City sees average daytime highs of 91°F and overnight lows near 61°F, with 0.1 in of rain across 0.6 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 94°F in the first days to 87°F by the end. 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 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is South Yuba City's 3rd-clearest and 12th-windiest month. For the whole year in context, see South Yuba City's year-round climate.

Daytime high
91°
4th warmest
Overnight low
61°
9th coldest
Rainfall
0.1 in
0.6 wet days
Daylight
12 h 18 min
5:53 AM – 6:08 PM
Cloud cover
14%
3rd clearest
Wind
5 mph
12th windiest
Solar energy
5.97 kWh/m²
Travel score
5.0
out of 10

South Yuba City is unincorporated community and former census-designated place in Sutter 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

Highs ease over the month, from about 94°F in the first days to 87°F by the end.

A typical September day in South Yuba City reaches about 91°F in the afternoon and slips back to 61°F overnight — a 30°F spread between the day's warmth and the night's chill. On most days the high lands between 81°F and 99°F. Set against its neighbours, September runs about 5°F cooler than August and about 10°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19463
29463
39463
49463
59363
69363
79362
89262
99262
109262
119262
129162
139162
149161
159161
169061
179061
189061
199061
208960
218960
228960
238960
248960
258860
268859
278759
288759
298759
308658

How September really feels in South Yuba City

Once humidity and wind are folded in, September averages 19 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
19
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

South Yuba City weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan59° / 42°4.49.89.64.5
Feb63° / 45°4.08.910.55.6
Mar68° / 48°3.38.911.76.6
Apr75° / 52°1.55.5137.6
May85° / 58°0.93.614.16.5
Jun93° / 64°0.2114.73.9
Jul97° / 65°0.00.114.52.5
Aug96° / 64°0.00.213.53.2
Sep91° / 61°0.10.612.35.0
Oct80° / 55°1.13.1117.9
Nov67° / 47°2.36.29.96.8
Dec58° / 42°4.19.79.34.4

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 6% of September, with mostly cloudy or overcast conditions the remaining 8%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1955
2955
3955
4955
5955
6946
7946
8946
9946
10937
11937
12928
13928
14928
15928
16928
17928
18928
19928
20928
21928
22928
23919
249010
259010
269010
278911
288911
298911
308911

Chance of precipitation in September

Any precipitation

South Yuba City 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 3% and peaks near 5% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
11
21
31
41
51
61
71
81
91
101
111
122
132
142
152
162
173
183
193
203
213
224
234
244
254
264
274
285
295
305

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 86% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
179183
280173
381163
482162
583152
683152
783152
884142
984142
1084142
1184142
1285141
1385141
1486131
1586131
1686131
1786131
1886131
1987121
2088120
2189110
2289110
2390100
2490100
2590100
2690100
2790100
2890100
2990100
3090100

Wind in September

Winds average 5 mph in September, the calmest month.

Across September, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 5:39 AM to 6:07 AM, and sunset from 6:33 PM to 5:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:396:33
212.95:406:32
312.85:416:30
412.85:426:28
512.75:436:27
612.75:446:25
712.65:456:23
812.65:466:22
912.65:476:20
1012.55:486:18
1112.55:496:17
1212.45:506:15
1312.45:516:13
1412.35:516:12
1512.35:526:10
1612.35:536:08
1712.25:546:07
1812.25:556:05
1912.15:566:03
2012.15:576:02
2112.05:586:00
2212.05:595:58
2311.96:005:57
2411.96:015:55
2511.96:025:53
2611.86:035:52
2711.86:045:50
2811.76:055:48
2911.76:065:47
3011.66:075:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.97 kWh/m².

For context, solar energy here swings from a low near 2.02 kWh/m² to a high of 8.21 kWh/m² in July across the year — September's 5.97 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.7Intense
26.7Intense
36.6Intense
46.6Intense
56.5Intense
66.5Intense
76.4Intense
86.4Intense
96.3Intense
106.3Intense
116.2Intense
126.2Intense
136.1Intense
146.0Intense
156.0Bright
165.9Bright
175.9Bright
185.8Bright
195.8Bright
205.7Bright
215.7Bright
225.6Bright
235.6Bright
245.5Bright
255.4Bright
265.4Bright
275.3Bright
285.3Bright
295.2Bright
305.2Bright
Planning a trip in September

Hazard calendar for South Yuba City

In seasonPeak

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

South Yuba City's rainy season runs November–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 South Yuba City?

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

5.0
Sightseeing
7th-best month of the year
8.3
Beach & pool
1st-best month of the year

September is a reasonable time to visit South Yuba City for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for South Yuba City in September

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

In September, South Yuba City sees daytime highs around 91°F and nights near 61°F. Pack light clothes. Worth having: sun protection.

light clothessun protection

UV index in South Yuba City in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in South Yuba City peaks around June 22 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 22UV 10Dec 14UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Low
Dec2Low

Air quality in South Yuba City 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 South Yuba City is worst in September — around 41 µg/m³ PM2.5 (poor), about 3.8× the cleanest month (June, 11 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModeratePoorModerateSep 1140 µg/m³Jun 911 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb15Moderate
Mar18Moderate
Apr15Moderate
May11Good
Jun11Good
Jul21Moderate
Aug37Poor
Sep41Poor
Oct21Moderate
Nov31Moderate
Dec13Moderate
Location & terrain

Where is South Yuba City?

South Yuba City sits at 39.1°N, 121.6°W, 52 ft above sea level, in United States. The nearest listed city is Yuba City, 1.9 mi away.

Topography around South Yuba City

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

Within 2 miles, the terrain around South Yuba City has only modest variations in elevation — a maximum elevation change of 49 ft around an average of 56 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,040 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,538 ft.

The land around South Yuba City is covered by artificial surfaces (44%) and trees (35%) within 2 miles, cropland (40%), grassland (28%) and trees (22%) within 10 miles, and trees (43%), grassland (28%) and cropland (22%) within 50 miles.

2 miles
49 ft
10 miles
1,040 ft
50 miles
5,538 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Yuba City 1.9 mi · Linda 5.0 mi · Lincoln 24 mi · Oroville 28 mi · Woodland 31 mi · Rio Linda 31 mi · Rocklin 31 mi · Roseville 32 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 South Yuba City (39.1166°, -121.6391°, elevation 52 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).