Eureka in Fall
In fall (September, October and November), Eureka sees average daytime highs around 58°F and overnight lows near 52°F, with 9.2 in of rain over about 21 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.
Over the season highs ease from about 61°F in early September to 54°F by late November. The sky is clear or mostly clear about 45% of the time across fall, and the air most often feels dry.
Fall is Eureka's 2nd-best season to visit on our travel score. Eureka has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see Eureka's year-round climate.
- Avg daytime high
- 58°F
- 2nd-warmest season
- Avg overnight low
- 52°F
- Rainfall
- 9.2 in
- 21 wet days
- Avg wind
- 8 mph
- Travel score
- 4.9
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Eureka in Fall
Over the season highs ease from about 61°F in early September to 54°F by late November.
A typical fall day in Eureka reaches about 58°F and drops to 52°F overnight. The warmest of the three months is September, the coolest November.
Eureka 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 | 53° / 46° | 8.0 | 15.3 | 9.4 | 2.6 |
| Feb | 53° / 46° | 6.7 | 13.4 | 10.4 | 2.6 |
| Mar | 53° / 47° | 7.0 | 14.7 | 11.7 | 2.6 |
| Apr | 53° / 48° | 4.1 | 11.8 | 13.1 | 3.0 |
| May | 55° / 50° | 2.1 | 7 | 14.2 | 3.9 |
| Jun | 57° / 52° | 0.9 | 3.7 | 14.9 | 4.9 |
| Jul | 60° / 53° | 0.1 | 0.8 | 14.6 | 6.0 |
| Aug | 61° / 54° | 0.2 | 0.9 | 13.6 | 6.3 |
| Sep | 61° / 54° | 0.6 | 2.3 | 12.3 | 6.3 |
| Oct | 59° / 52° | 2.9 | 6.3 | 10.9 | 5.1 |
| Nov | 55° / 49° | 5.7 | 12.5 | 9.7 | 3.3 |
| Dec | 53° / 47° | 9.6 | 15.6 | 9.1 | 2.6 |
Cloud cover in Fall
The sky is clear or mostly clear about 45% of the time across fall.
Chance of precipitation in Fall
Eureka gets around 9.2 in of rain over 21 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 8 mph across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 hours in early September to 9 h 18 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 3.8 kWh/m².
Hazard calendar for Eureka
In fall, Eureka overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Eureka's rainy season runs November–March, when most of the year's rain falls.
Is fall a good time to visit Eureka?
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 a reasonable time to visit Eureka for sightseeing.
What to pack for Eureka in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Eureka sees daytime highs around 58°F and nights near 52°F. Worth packing: a warm layer, rain gear and sun protection. About 21 days see rain.
Sea temperature near Eureka in Fall
The nearest coast averages about 54°F across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 55°F and coldest in March near 51°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) | 52 | 52 | 51 | 52 | 52 | 53 | 54 | 55 | 55 | 54 | 53 | 53 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 52 | Bracing |
| Feb | 52 | Bracing |
| Mar | 51 | Bracing |
| Apr | 52 | Bracing |
| May | 52 | Bracing |
| Jun | 53 | Bracing |
| Jul | 54 | Bracing |
| Aug | 55 | Bracing |
| Sep | 55 | Bracing |
| Oct | 54 | Bracing |
| Nov | 53 | Bracing |
| Dec | 53 | Bracing |
UV index in Eureka 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 Eureka peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 9 | 10 | 9 | 8 | 5 | 5 | 2 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 9 | Very high |
| Jun | 10 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 5 | High |
| Oct | 5 | Moderate |
| Nov | 2 | Low |
| Dec | 2 | Low |
Air quality in Eureka 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 Eureka is worst in September — around 35 µg/m³ PM2.5 (poor), about 6.3× the cleanest month (December, 6 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) | 6 | 7 | 8 | 9 | 8 | 9 | 11 | 28 | 35 | 8 | 7 | 6 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Poor | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 6 | Good |
| Feb | 7 | Good |
| Mar | 8 | Good |
| Apr | 9 | Good |
| May | 8 | Good |
| Jun | 9 | Good |
| Jul | 11 | Good |
| Aug | 28 | Moderate |
| Sep | 35 | Poor |
| Oct | 8 | Good |
| Nov | 7 | Good |
| Dec | 6 | Good |
Where is Eureka?
Eureka sits at 40.8°N, 124.2°W, 39 ft above sea level, in United States. The nearest listed city is Bayside, 6.2 mi away.
Topography around Eureka
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Eureka.
Within 2 miles, the terrain around Eureka has only modest variations in elevation — a maximum elevation change of 302 ft around an average of 39 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,293 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,415 ft.
The land around Eureka is covered by water (35%) and artificial surfaces (32%) within 2 miles, water (46%) and trees (39%) within 10 miles, and trees (64%) and water (30%) 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 Eureka (40.8021°, -124.1637°, elevation 39 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.