Aliso Viejo in Fall

In fall (September, October and November), Aliso Viejo sees average daytime highs around 71°F and overnight lows near 61°F, with 1.5 in of rain over about 5 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.

Over the season highs ease from about 75°F in early September to 65°F by late November. The sky is clear or mostly clear about 72% of the time across fall, and the air most often feels comfortable.

Fall is Aliso Viejo's 2nd-best season to visit on our travel score. For the whole year in context, see Aliso Viejo's year-round climate.

Avg daytime high
71°F
2nd-warmest season
Avg overnight low
61°F
Rainfall
1.5 in
5 wet days
Avg wind
5 mph
Travel score
8.5
2nd-best season
Months
Sep · Oct · Nov

Temperature in Aliso Viejo in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 75°F in early September to 65°F by late November.

A typical fall day in Aliso Viejo reaches about 71°F and drops to 61°F overnight. The warmest of the three months is September, the coolest November.

40°50°60°70°80°SepOctNov

Aliso Viejo weather by month

How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan62° / 51°2.65.5106.2
Feb62° / 52°3.16.310.85.9
Mar63° / 53°1.85.711.76.3
Apr64° / 55°0.82.912.87.2
May66° / 58°0.31.713.77.7
Jun69° / 61°0.10.414.28.5
Jul73° / 64°0.10.4149.2
Aug75° / 66°0.00.213.29.6
Sep74° / 65°0.10.612.29.3
Oct71° / 61°0.6211.28.5
Nov67° / 56°0.82.810.37.7
Dec62° / 51°1.94.89.86.4

Cloud cover in Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 72% of the time across fall.

0%25%50%75%100%SepOctNov

Chance of precipitation in Fall

Any precipitation

Aliso Viejo gets around 1.5 in of rain over 5 wet days across fall. The line is the day-by-day chance of measurable precipitation.

0%10%20%30%SepOctNov

Humidity in Fall

DryComfortableHumidMuggyOppressiveMiserable

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

0%25%50%75%100%SepOctNov

Wind in Fall

Winds average 5 mph across fall.

0246810SepOctNov

Sunrise & sunset in Fall

DaylightNight

Daylight runs from about 12 h 42 min in early September to 10 hours by late November. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMSepOctNov

Solar energy in Fall

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across fall, about 4.8 kWh/m².

0246SepOctNov
Planning a trip in fall

Is fall a good time to visit Aliso Viejo?

Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

8.5
Sightseeing
2nd-best month of the year
5.6
Beach & pool
2nd-best month of the year

fall is one of the better times to visit Aliso Viejo for general sightseeing.

What to pack for Aliso Viejo in Fall

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

In fall, Aliso Viejo sees daytime highs around 71°F and nights near 61°F. Pack sun protection. Worth having: light clothes. About 5 days see rain.

sun protectionlight clothes

Sea temperature near Aliso Viejo in Fall

The nearest coast averages about 66°F across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 9 mi away) is warmest in August at about 69°F and coldest in February near 59°F.

It's comfortable for a long swim from Jul 13 to Sep 28 — about 2.6 months when the water holds above 68°F.

60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°F)Comfort
Jan59Cool
Feb59Cool
Mar59Cool
Apr60Cool
May63Cool
Jun65Cool
Jul68Refreshing
Aug69Refreshing
Sep69Refreshing
Oct67Cool
Nov64Cool
Dec60Cool

UV index in Aliso Viejo in Fall

LowModerateHighVery highExtreme

Clear-sky midday UV across fall averages 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 Aliso Viejo peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateVery highExtremeVery highHighModerateJun 23UV 10Dec 16UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May8Very high
Jun11Extreme
Jul10Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Aliso Viejo in Fall

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Aliso Viejo is worst in September — around 49 µg/m³ PM2.5 (poor), about 4.0× the cleanest month (May, 12 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateSep 1447 µg/m³May 1713 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb19Moderate
Mar19Moderate
Apr17Moderate
May12Moderate
Jun17Moderate
Jul19Moderate
Aug32Moderate
Sep49Poor
Oct21Moderate
Nov21Moderate
Dec18Moderate
Location & terrain

Where is Aliso Viejo?

Aliso Viejo sits at 33.6°N, 117.7°W, 469 ft above sea level, in United States. The nearest listed city is Laguna Woods, 3.1 mi away.

Topography around Aliso Viejo

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

Within 2 miles, the terrain around Aliso Viejo has significant variations in elevation — a maximum elevation change of 935 ft around an average of 400 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,663 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,967 ft.

The land around Aliso Viejo is covered by artificial surfaces (44%) and trees (35%) within 2 miles, artificial surfaces (31%), water (26%) and trees (21%) within 10 miles, and water (36%) and artificial surfaces (26%) within 50 miles.

2 miles
935 ft
10 miles
1,663 ft
50 miles
9,967 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
Fall weather nearby: Laguna Woods 3.1 mi · Laguna Niguel 3.1 mi · Laguna Hills 3.1 mi · Laguna Beach 3.7 mi · Mission Viejo 3.7 mi · Ladera Ranch 5.6 mi · San Juan Capistrano 5.6 mi · Lake Forest 6.2 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 Aliso Viejo (33.565°, -117.7271°, elevation 469 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.