Ripon weather in September

In September, Ripon sees average daytime highs of 86°F and overnight lows near 60°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 89°F in the first days to 84°F by the end. The sky is clear or mostly clear about 87% 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 42 min by month's end. Set against the rest of the year, September is Ripon's 3rd-clearest and 8th-windiest month. For the whole year in context, see Ripon's year-round climate.

Daytime high
86°
4th warmest
Overnight low
60°
9th coldest
Rainfall
0.1 in
0.6 wet days
Daylight
12 h 12 min
5:52 AM – 6:06 PM
Cloud cover
13%
3rd clearest
Wind
5 mph
8th windiest
Solar energy
6.09 kWh/m²
Travel score
6.6
out of 10

Ripon is city in California, United States.

Density
1,072/km²
people per km²
Founded
1945

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 89°F in the first days to 84°F by the end.

A typical September day in Ripon reaches about 86°F in the afternoon and slips back to 60°F overnight — a 26°F spread between the day's warmth and the night's chill. On most days the high lands between 79°F and 94°F. Set against its neighbours, September runs about 5°F cooler than August and about 9°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19062
28962
38962
48962
58962
68962
78861
88861
98861
108861
118761
128760
138760
148760
158660
168660
178660
188659
198659
208559
218559
228559
238559
248558
258458
268458
278458
288358
298358
308357

How September really feels in Ripon

Once humidity and wind are folded in, September averages 1 day 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
1
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.

Ripon 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
Jan58° / 42°3.68.49.74.5
Feb62° / 44°3.38.710.55.5
Mar67° / 47°2.88.311.76.6
Apr73° / 50°1.44.712.97.8
May82° / 56°0.83147.6
Jun89° / 61°0.10.814.65.6
Jul92° / 64°0.00.114.34.5
Aug91° / 63°0.00.213.55.1
Sep86° / 60°0.10.612.36.6
Oct78° / 53°0.92.6118.5
Nov66° / 46°1.85.5106.8
Dec58° / 41°3.48.39.44.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 87% 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 6%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1973
2964
3964
4964
5964
6964
7964
8964
9955
10955
11955
12955
13955
14955
15946
16946
17946
18946
19928
20928
21928
22928
23928
24928
25919
269010
279010
289010
299010
309010

Chance of precipitation in September

Any precipitation

Ripon 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
51
62
72
82
92
102
112
122
132
142
152
162
172
182
192
202
212
222
232
243
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 74% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1692641
2702541
3712441
4722341
5732241
6732241
7742141
8752131
9752131
10752131
11752131
12752131
13742231
14752230
15752320
16742420
17742420
18742420
19732520
20742510
21742510
22742510
23752410
24752410
25752410
26762310
27772210
28782110
29792010
30801910

Wind in September

Winds average 5 mph in September.

Across September, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
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 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over September. Sunrise moves from 5:39 AM to 6:04 AM, and sunset from 6:30 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:396:30
212.85:396:28
312.85:406:27
412.75:416:25
512.75:426:24
612.75:436:22
712.65:446:20
812.65:456:19
912.55:466:17
1012.55:466:16
1112.45:476:14
1212.45:486:12
1312.45:496:11
1412.35:506:09
1512.35:516:08
1612.25:526:06
1712.25:536:04
1812.25:536:03
1912.15:546:01
2012.15:556:00
2112.05:565:58
2212.05:575:56
2311.95:585:55
2411.95:595:53
2511.96:005:51
2611.86:005:50
2711.86:015:48
2811.76:025:47
2911.76:035:45
3011.76:045:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.09 kWh/m².

For context, solar energy here swings from a low near 2.28 kWh/m² to a high of 8.24 kWh/m² in June across the year — September's 6.09 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
96.4Intense
106.4Intense
116.3Intense
126.3Intense
136.2Intense
146.2Intense
156.1Intense
166.1Intense
176.0Intense
186.0Bright
195.9Bright
205.8Bright
215.8Bright
225.7Bright
235.7Bright
245.6Bright
255.6Bright
265.5Bright
275.5Bright
285.4Bright
295.4Bright
305.3Bright
Planning a trip in September

Is September a good time to visit Ripon?

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

6.6
Sightseeing
5th-best month of the year
9.0
Beach & pool
1st-best month of the year

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

What to pack for Ripon in September

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

In September, Ripon sees daytime highs around 86°F and nights near 60°F. Pack light clothes and sun protection.

light clothessun protection

UV index in Ripon 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 Ripon peaks around June 21 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 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 highVery highHighModerateJun 21UV 10Dec 17UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun10Extreme
Jul10Very high
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in Ripon 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 Ripon is worst in August — around 29 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (June, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 1928 µg/m³Jun 118 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb14Moderate
Mar14Moderate
Apr11Good
May9Good
Jun8Good
Jul15Moderate
Aug29Moderate
Sep22Moderate
Oct17Moderate
Nov15Moderate
Dec12Moderate
Location & terrain

Where is Ripon?

Ripon sits at 37.7°N, 121.1°W, 69 ft above sea level, in United States. The nearest listed city is Manteca, 6.2 mi away.

Topography around Ripon

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

Within 2 miles, the terrain around Ripon has only modest variations in elevation — a maximum elevation change of 98 ft around an average of 66 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 187 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,259 ft.

The land around Ripon is covered by trees (38%) and artificial surfaces (28%) within 2 miles, trees (37%) and cropland (29%) within 10 miles, and grassland (44%) and trees (26%) within 50 miles.

2 miles
98 ft
10 miles
187 ft
50 miles
4,259 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Manteca 6.2 mi · Modesto 9.9 mi · Lathrop 9.9 mi · Riverbank 11 mi · Ceres 14 mi · Oakdale 16 mi · Tracy 17 mi · Stockton 17 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 Ripon (37.7416°, -121.1244°, elevation 69 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).