Folsom weather in September

In September, Folsom sees average daytime highs of 88°F and overnight lows near 59°F, with 0.2 in of rain across 0.8 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 91°F in the first days to 84°F by the end. The sky is clear or mostly clear about 85% 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 Folsom's 3rd-clearest and 10th-windiest month. For the whole year in context, see Folsom's year-round climate.

Daytime high
88°
4th warmest
Overnight low
59°
9th coldest
Rainfall
0.2 in
0.8 wet days
Daylight
12 h 12 min
5:52 AM – 6:06 PM
Cloud cover
15%
3rd clearest
Wind
5 mph
10th windiest
Solar energy
5.99 kWh/m²
Travel score
6.1
out of 10

Folsom is city in Sacramento County, California, United States.

Density
1,213/km²
people per km²
Founded
1946

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 91°F in the first days to 84°F by the end.

A typical September day in Folsom reaches about 88°F in the afternoon and slips back to 59°F overnight — a 29°F spread between the day's warmth and the night's chill. On most days the high lands between 78°F and 97°F. Set against its neighbours, September runs about 4°F cooler than August and about 10°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19161
29161
39161
49061
59061
69061
79060
88960
98960
108960
118960
128859
138859
148859
158859
168759
178758
188758
198758
208758
218658
228658
238658
248657
258557
268557
278557
288556
298456
308456

How September really feels in Folsom

Once humidity and wind are folded in, September averages 7 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
7
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.

Folsom 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
Jan57° / 40°5.610.19.64.1
Feb61° / 43°5.39.710.55.1
Mar66° / 46°4.79.611.76.2
Apr72° / 49°2.26.4137.4
May80° / 55°1.34.514.17.7
Jun88° / 60°0.31.214.75.7
Jul93° / 63°0.00.114.44.3
Aug92° / 62°0.00.113.54.6
Sep88° / 59°0.20.812.36.1
Oct78° / 52°1.63.3118.3
Nov65° / 44°3.06.99.96.4
Dec57° / 40°5.610.49.34.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 85% 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 8%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1955
2955
3955
4955
5955
6955
7955
8946
9946
10937
11937
12937
13937
14937
15928
16928
17928
18928
19928
20919
21919
22919
23919
249010
259010
269010
279010
289010
299010
309010

Chance of precipitation in September

Any precipitation

Folsom gets around 0.2 in of rain over 0.8 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 6% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
11
21
31
41
51
61
71
81
92
102
112
122
132
142
152
163
173
183
193
203
213
224
234
244
254
265
275
285
296
306

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 (%)
184142
284142
385132
485132
586122
686122
786122
886122
987112
1088111
1189101
1289101
1389101
1489101
159190
169190
179190
189190
199190
209280
219280
229280
239280
249370
259370
269370
279370
289370
299460
309460

Wind in September

Winds average 5 mph in September.

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 5:38 AM to 6:05 AM, and sunset from 6:31 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:386:31
212.85:396:29
312.85:406:28
412.85:416:26
512.75:426:25
612.75:426:23
712.65:436:21
812.65:446:20
912.55:456:18
1012.55:466:16
1112.55:476:15
1212.45:486:13
1312.45:496:11
1412.35:506:10
1512.35:516:08
1612.25:526:06
1712.25:536:05
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
2511.96:005:52
2611.86:015:50
2711.86:025:48
2811.76:035:47
2911.76:045:45
3011.66:055:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.99 kWh/m².

For context, solar energy here swings from a low near 2.07 kWh/m² to a high of 8.22 kWh/m² in July across the year — September's 5.99 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.7Intense
26.7Intense
36.7Intense
46.6Intense
56.5Intense
66.5Intense
76.5Intense
86.4Intense
96.3Intense
106.3Intense
116.2Intense
126.2Intense
136.1Intense
146.1Intense
156.0Intense
166.0Bright
175.9Bright
185.8Bright
195.8Bright
205.7Bright
215.7Bright
225.6Bright
235.6Bright
245.5Bright
255.5Bright
265.4Bright
275.3Bright
285.3Bright
295.2Bright
305.2Bright
Planning a trip in September

Hazard calendar for Folsom

In seasonPeak

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

Folsom'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 Folsom?

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

6.1
Sightseeing
6th-best month of the year
8.8
Beach & pool
1st-best month of the year

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

What to pack for Folsom in September

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

In September, Folsom sees daytime highs around 88°F and nights near 59°F. Pack light clothes. Worth having: sun protection.

light clothessun protection

UV index in Folsom 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 Folsom peaks around June 21 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 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 21UV 10Dec 13UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Low
Dec2Low

Air quality in Folsom 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 Folsom 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 Folsom?

Folsom sits at 38.7°N, 121.2°W, 220 ft above sea level, in United States. The nearest listed city is Orangevale, 2.5 mi away.

Topography around Folsom

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

Within 2 miles, the terrain around Folsom has only modest variations in elevation — a maximum elevation change of 404 ft around an average of 279 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,552 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,618 ft.

The land around Folsom is covered by trees (45%) and artificial surfaces (43%) within 2 miles, trees (34%), grassland (32%) and artificial surfaces (27%) within 10 miles, and trees (45%), grassland (27%) and cropland (20%) within 50 miles.

2 miles
404 ft
10 miles
1,552 ft
50 miles
7,618 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Orangevale 2.5 mi · El Dorado Hills 5.0 mi · Fair Oaks 5.6 mi · Granite Bay 6.2 mi · Citrus Heights 6.2 mi · Roseville 8.1 mi · Rocklin 8.7 mi · Antelope 8.7 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 Folsom (38.678°, -121.1761°, elevation 220 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).