Walnut Creek in Fall
In fall (September, October and November), Walnut Creek sees average daytime highs around 74°F and overnight lows near 52°F, with 2.6 in of rain over about 9 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.
Over the season highs ease from about 82°F in early September to 60°F by late November. The sky is clear or mostly clear about 66% of the time across fall, and the air most often feels dry.
Fall is Walnut Creek's 2nd-best season to visit on our travel score. For the whole year in context, see Walnut Creek's year-round climate.
- Avg daytime high
- 74°F
- 2nd-warmest season
- Avg overnight low
- 52°F
- Rainfall
- 2.6 in
- 9 wet days
- Avg wind
- 5 mph
- Travel score
- 7.9
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Walnut Creek in Fall
Over the season highs ease from about 82°F in early September to 60°F by late November.
A typical fall day in Walnut Creek reaches about 74°F and drops to 52°F overnight. The warmest of the three months is September, the coolest November.
Walnut Creek 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 | 57° / 42° | 3.7 | 8.9 | 9.7 | 4.2 |
| Feb | 61° / 44° | 3.7 | 8.7 | 10.5 | 5.1 |
| Mar | 65° / 47° | 2.8 | 8.3 | 11.7 | 6.3 |
| Apr | 69° / 49° | 1.3 | 4.7 | 13 | 7.4 |
| May | 74° / 52° | 0.7 | 2.9 | 14 | 8.5 |
| Jun | 80° / 55° | 0.1 | 0.8 | 14.6 | 8.8 |
| Jul | 82° / 57° | 0.0 | 0.2 | 14.4 | 8.8 |
| Aug | 82° / 57° | 0.1 | 0.2 | 13.5 | 8.7 |
| Sep | 81° / 56° | 0.1 | 0.4 | 12.3 | 8.7 |
| Oct | 75° / 53° | 0.8 | 2.8 | 11 | 8.6 |
| Nov | 65° / 47° | 1.7 | 5.4 | 10 | 6.5 |
| Dec | 57° / 43° | 3.3 | 8.6 | 9.4 | 4.3 |
Cloud cover in Fall
The sky is clear or mostly clear about 66% of the time across fall.
Chance of precipitation in Fall
Walnut Creek gets around 2.6 in of rain over 9 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 5 mph across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 54 min in early September to 9 h 36 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 4.3 kWh/m².
Is fall a good time to visit Walnut Creek?
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 Walnut Creek for general sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Walnut Creek in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Walnut Creek sees daytime highs around 74°F and nights near 52°F. Pack light clothes. Worth having: sun protection. About 9 days see rain.
Sea temperature near Walnut Creek in Fall
The nearest coast averages about 57°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 30 mi away) is warmest in September at about 58°F and coldest in April near 53°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 53 | 53 | 54 | 53 | 53 | 54 | 56 | 58 | 58 | 57 | 55 | 54 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 53 | Bracing |
| Feb | 53 | Bracing |
| Mar | 54 | Bracing |
| Apr | 53 | Bracing |
| May | 53 | Bracing |
| Jun | 54 | Bracing |
| Jul | 56 | Bracing |
| Aug | 58 | Bracing |
| Sep | 58 | Bracing |
| Oct | 57 | Bracing |
| Nov | 55 | Bracing |
| Dec | 54 | Bracing |
UV index in Walnut Creek in Fall
Clear-sky midday UV across fall averages around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Walnut Creek peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 4 | 6 | 8 | 10 | 10 | 10 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 10 | Very high |
| Jul | 10 | Very high |
| Aug | 10 | Very high |
| Sep | 6 | High |
| Oct | 5 | High |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Walnut Creek 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 Walnut Creek is worst in September — around 29 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (June, 7 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) | 13 | 13 | 13 | 10 | 8 | 7 | 10 | 25 | 29 | 27 | 16 | 12 |
| Level | Moderate | Moderate | Moderate | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 13 | Moderate |
| Mar | 13 | Moderate |
| Apr | 10 | Good |
| May | 8 | Good |
| Jun | 7 | Good |
| Jul | 10 | Good |
| Aug | 25 | Moderate |
| Sep | 29 | Moderate |
| Oct | 27 | Moderate |
| Nov | 16 | Moderate |
| Dec | 12 | Good |
Where is Walnut Creek?
Walnut Creek sits at 37.9°N, 122.1°W, 171 ft above sea level, in United States. The nearest listed city is Pleasant Hill, 3.1 mi away.
Topography around Walnut Creek
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Walnut Creek.
Within 2 miles, the terrain around Walnut Creek has only modest variations in elevation — a maximum elevation change of 682 ft around an average of 230 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,816 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,449 ft.
The land around Walnut Creek is covered by trees (53%) and artificial surfaces (37%) within 2 miles, trees (45%) and grassland (34%) within 10 miles, and grassland (28%), trees (24%) and water (21%) 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 Walnut Creek (37.9063°, -122.065°, elevation 171 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.