Fullerton in Fall
In fall (September, October and November), Fullerton sees average daytime highs around 75°F and overnight lows near 60°F, with 1.4 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 81°F in early September to 67°F by late November. The sky is clear or mostly clear about 72% of the time across fall, and the air most often feels dry.
Fall is Fullerton's 2nd-best season to visit on our travel score. For the whole year in context, see Fullerton's year-round climate.
- Avg daytime high
- 75°F
- 2nd-warmest season
- Avg overnight low
- 60°F
- Rainfall
- 1.4 in
- 5 wet days
- Avg wind
- 4 mph
- Travel score
- 8.6
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Fullerton in Fall
Over the season highs ease from about 81°F in early September to 67°F by late November.
A typical fall day in Fullerton reaches about 75°F and drops to 60°F overnight. The warmest of the three months is September, the coolest November.
Fullerton 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.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 64° / 49° | 2.8 | 5.2 | 10 | 6.8 |
| Feb | 65° / 50° | 3.1 | 6.1 | 10.7 | 6.7 |
| Mar | 66° / 53° | 1.8 | 5.1 | 11.7 | 7.0 |
| Apr | 69° / 55° | 0.7 | 2.6 | 12.8 | 7.9 |
| May | 71° / 58° | 0.3 | 1.5 | 13.7 | 8.3 |
| Jun | 74° / 61° | 0.1 | 0.3 | 14.2 | 9.1 |
| Jul | 79° / 64° | 0.1 | 0.4 | 14 | 9.0 |
| Aug | 81° / 65° | 0.0 | 0.1 | 13.3 | 8.9 |
| Sep | 80° / 64° | 0.1 | 0.5 | 12.2 | 8.8 |
| Oct | 76° / 60° | 0.6 | 1.9 | 11.1 | 8.8 |
| Nov | 70° / 54° | 0.7 | 2.4 | 10.2 | 8.1 |
| Dec | 65° / 49° | 1.9 | 4.9 | 9.8 | 6.9 |
Cloud cover in Fall
The sky is clear or mostly clear about 72% of the time across fall.
Chance of precipitation in Fall
Fullerton gets around 1.4 in of rain over 5 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 4 mph across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 42 min in early September to 9 h 54 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 4.8 kWh/m².
Is fall a good time to visit Fullerton?
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.
fall is one of the better times to visit Fullerton for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Fullerton in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Fullerton sees daytime highs around 75°F and nights near 60°F. Pack sun protection. Worth having: light clothes. About 5 days see rain.
Sea temperature near Fullerton 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 17 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 59 | 59 | 59 | 60 | 63 | 65 | 68 | 69 | 69 | 67 | 64 | 60 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing | Refreshing | Cool | Cool | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 59 | Cool |
| Feb | 59 | Cool |
| Mar | 59 | Cool |
| Apr | 60 | Cool |
| May | 63 | Cool |
| Jun | 65 | Cool |
| Jul | 68 | Refreshing |
| Aug | 69 | Refreshing |
| Sep | 69 | Refreshing |
| Oct | 67 | Cool |
| Nov | 64 | Cool |
| Dec | 60 | Cool |
UV index in Fullerton in Fall
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 Fullerton peaks around July 11 at about 11 (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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 4 | 5 | 5 | 8 | 8 | 11 | 11 | 10 | 8 | 6 | 3 | 3 |
| Level | Moderate | Moderate | Moderate | Very high | Very high | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 5 | Moderate |
| Mar | 5 | Moderate |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 10 | Extreme |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 3 | Moderate |
| Dec | 3 | Moderate |
Air quality in Fullerton in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Fullerton 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 18 | 19 | 19 | 17 | 12 | 17 | 19 | 32 | 49 | 21 | 21 | 18 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 18 | Moderate |
| Feb | 19 | Moderate |
| Mar | 19 | Moderate |
| Apr | 17 | Moderate |
| May | 12 | Moderate |
| Jun | 17 | Moderate |
| Jul | 19 | Moderate |
| Aug | 32 | Moderate |
| Sep | 49 | Poor |
| Oct | 21 | Moderate |
| Nov | 21 | Moderate |
| Dec | 18 | Moderate |
Where is Fullerton?
Fullerton sits at 33.9°N, 117.9°W, 164 ft above sea level, in United States. The nearest listed city is Anaheim, 2.5 mi away.
Topography around Fullerton
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Fullerton.
Within 2 miles, the terrain around Fullerton has only modest variations in elevation — a maximum elevation change of 384 ft around an average of 197 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,654 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 10,010 ft.
The land around Fullerton is covered by artificial surfaces (83%) within 2 miles, artificial surfaces (76%) within 10 miles, and water (29%) and artificial surfaces (25%) within 50 miles.
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
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 Fullerton (33.8703°, -117.9253°, elevation 164 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.