Ukiah weather in December
In December, Ukiah sees average daytime highs of 53°F and overnight lows near 36°F, with 7.8 in of precipitation across 12.2 wet days and about 9.3 hours of daylight. It is the 12th-warmest and 1st-wettest month of the year here.
Day-to-day highs hold fairly steady near 53°F through the month. The sky is clear or mostly clear about 31% of the time in December, and the air most often feels dry.
Daylight stretches from about 9 h 24 min at the start of December to 9 h 18 min by month's end. Set against the rest of the year, December is Ukiah's 11th-clearest and 6th-windiest month. For the whole year in context, see Ukiah's year-round climate.
- Daytime high
- 53°
- 12th warmest
- Overnight low
- 36°
- 1st coldest
- Precipitation
- 7.8 in
- 12.2 wet days
- Daylight
- 9 h 18 min
- 7:31 AM – 4:47 PM
- Cloud cover
- 62%
- 11th clearest
- Wind
- 4 mph
- 6th windiest
- Solar energy
- 1.92 kWh/m²
- Travel score
- 2.9
- out of 10
Ukiah is city in and county seat of Mendocino County, California, United States.
- Density
- 1,301/km²
- people per km²
- Founded
- 1876
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in December
Day-to-day highs hold fairly steady near 53°F through the month.
A typical December day in Ukiah reaches about 53°F in the afternoon and slips back to 36°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 45°F and 61°F. Set against its neighbours, December runs about 7°F cooler than November and on par with January.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 55 | 55 | 55 | 55 | 54 | 54 | 54 | 54 | 54 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 |
| Avg low (°F) | 38 | 37 | 37 | 37 | 37 | 37 | 37 | 37 | 37 | 37 | 37 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 | 35 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 55 | 38 |
| 2 | 55 | 37 |
| 3 | 55 | 37 |
| 4 | 55 | 37 |
| 5 | 54 | 37 |
| 6 | 54 | 37 |
| 7 | 54 | 37 |
| 8 | 54 | 37 |
| 9 | 54 | 37 |
| 10 | 53 | 37 |
| 11 | 53 | 37 |
| 12 | 53 | 36 |
| 13 | 53 | 36 |
| 14 | 53 | 36 |
| 15 | 53 | 36 |
| 16 | 53 | 36 |
| 17 | 53 | 36 |
| 18 | 53 | 36 |
| 19 | 52 | 36 |
| 20 | 52 | 35 |
| 21 | 52 | 35 |
| 22 | 52 | 35 |
| 23 | 52 | 35 |
| 24 | 52 | 35 |
| 25 | 52 | 35 |
| 26 | 52 | 35 |
| 27 | 52 | 35 |
| 28 | 52 | 35 |
| 29 | 52 | 35 |
| 30 | 52 | 35 |
| 31 | 52 | 35 |
How December really feels in Ukiah
Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 12 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
The story in December is cold — wind chill drags the overnight "feels like" below the raw low.
Ukiah weather by month
How December compares with the rest of the year at a glance. December is the 12th-warmest and 1st-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 54° / 37° | 7.2 | 12.4 | 1.9 | 9.6 | 3.0 |
| Feb | 56° / 38° | 6.7 | 10.8 | 2.3 | 10.5 | 3.6 |
| Mar | 59° / 40° | 6.0 | 11.8 | 2 | 11.7 | 4.5 |
| Apr | 63° / 42° | 3.1 | 8.3 | 0.5 | 13 | 5.9 |
| May | 70° / 47° | 1.9 | 5.4 | 0 | 14.1 | 7.5 |
| Jun | 78° / 53° | 0.6 | 2.2 | 0 | 14.7 | 8.6 |
| Jul | 85° / 57° | 0.0 | 0.3 | 0 | 14.5 | 7.1 |
| Aug | 85° / 57° | 0.1 | 0.4 | 0 | 13.5 | 7.2 |
| Sep | 82° / 54° | 0.3 | 1.4 | 0 | 12.3 | 8.3 |
| Oct | 73° / 47° | 2.2 | 4.6 | 0 | 11 | 8.1 |
| Nov | 60° / 40° | 4.3 | 8.5 | 0.3 | 9.9 | 5.0 |
| Dec | 53° / 36° | 7.8 | 12.2 | 1.3 | 9.3 | 2.9 |
Cloud cover in December
The sky is clear or mostly clear about 31% of the time in December.
Beyond those clear spells, partly cloudy skies cover about 9% of December, with mostly cloudy or overcast conditions the remaining 59%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 45 | 45 | 43 | 43 | 42 | 41 | 41 | 40 | 41 | 41 | 40 | 40 | 40 | 40 | 40 | 40 | 41 | 41 | 41 | 41 | 42 | 41 | 41 | 41 | 40 | 40 | 40 | 39 | 39 | 39 | 38 |
| Cloudier (%) | 55 | 55 | 57 | 57 | 58 | 59 | 59 | 60 | 59 | 59 | 60 | 60 | 60 | 60 | 60 | 60 | 59 | 59 | 59 | 59 | 58 | 59 | 59 | 59 | 60 | 60 | 60 | 61 | 61 | 61 | 62 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 45 | 55 |
| 2 | 45 | 55 |
| 3 | 43 | 57 |
| 4 | 43 | 57 |
| 5 | 42 | 58 |
| 6 | 41 | 59 |
| 7 | 41 | 59 |
| 8 | 40 | 60 |
| 9 | 41 | 59 |
| 10 | 41 | 59 |
| 11 | 40 | 60 |
| 12 | 40 | 60 |
| 13 | 40 | 60 |
| 14 | 40 | 60 |
| 15 | 40 | 60 |
| 16 | 40 | 60 |
| 17 | 41 | 59 |
| 18 | 41 | 59 |
| 19 | 41 | 59 |
| 20 | 41 | 59 |
| 21 | 42 | 58 |
| 22 | 41 | 59 |
| 23 | 41 | 59 |
| 24 | 41 | 59 |
| 25 | 40 | 60 |
| 26 | 40 | 60 |
| 27 | 40 | 60 |
| 28 | 39 | 61 |
| 29 | 39 | 61 |
| 30 | 39 | 61 |
| 31 | 38 | 62 |
Chance of precipitation in December
Ukiah gets around 7.8 in of rain and snow over 12.2 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable precipitation averages around 39% and peaks near 43% on the wettest days, and about 1 day brings snow.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 37 | 38 | 38 | 39 | 40 | 41 | 41 | 42 | 42 | 43 | 43 | 43 | 42 | 42 | 41 | 41 | 40 | 39 | 39 | 38 | 37 | 37 | 37 | 36 | 36 | 36 | 36 | 36 | 36 | 37 | 37 |
| Snow chance (%) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 | 5 | 5 | 5 | 6 | 6 | 6 | 7 | 7 | 7 | 7 | 8 | 8 | 8 |
| Rain chance (%) | Snow chance (%) | |
|---|---|---|
| 1 | 37 | 2 |
| 2 | 38 | 2 |
| 3 | 38 | 2 |
| 4 | 39 | 2 |
| 5 | 40 | 2 |
| 6 | 41 | 2 |
| 7 | 41 | 2 |
| 8 | 42 | 2 |
| 9 | 42 | 3 |
| 10 | 43 | 3 |
| 11 | 43 | 3 |
| 12 | 43 | 3 |
| 13 | 42 | 3 |
| 14 | 42 | 3 |
| 15 | 41 | 4 |
| 16 | 41 | 4 |
| 17 | 40 | 4 |
| 18 | 39 | 4 |
| 19 | 39 | 5 |
| 20 | 38 | 5 |
| 21 | 37 | 5 |
| 22 | 37 | 6 |
| 23 | 37 | 6 |
| 24 | 36 | 6 |
| 25 | 36 | 7 |
| 26 | 36 | 7 |
| 27 | 36 | 7 |
| 28 | 36 | 7 |
| 29 | 36 | 8 |
| 30 | 37 | 8 |
| 31 | 37 | 8 |
Humidity in December
Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Dry (%) | |
|---|---|
| 1 | 100 |
| 2 | 100 |
| 3 | 100 |
| 4 | 100 |
| 5 | 100 |
| 6 | 100 |
| 7 | 100 |
| 8 | 100 |
| 9 | 100 |
| 10 | 100 |
| 11 | 100 |
| 12 | 100 |
| 13 | 100 |
| 14 | 100 |
| 15 | 100 |
| 16 | 100 |
| 17 | 100 |
| 18 | 100 |
| 19 | 100 |
| 20 | 100 |
| 21 | 100 |
| 22 | 100 |
| 23 | 100 |
| 24 | 100 |
| 25 | 100 |
| 26 | 100 |
| 27 | 100 |
| 28 | 100 |
| 29 | 100 |
| 30 | 100 |
| 31 | 100 |
Wind in December
Winds average 4 mph in December.
Across December, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 4 | calm |
| 2 | 4 | calm |
| 3 | 4 | calm |
| 4 | 4 | calm |
| 5 | 4 | calm |
| 6 | 4 | calm |
| 7 | 4 | calm |
| 8 | 4 | calm |
| 9 | 4 | calm |
| 10 | 4 | calm |
| 11 | 4 | calm |
| 12 | 4 | calm |
| 13 | 4 | calm |
| 14 | 4 | calm |
| 15 | 4 | calm |
| 16 | 4 | calm |
| 17 | 4 | calm |
| 18 | 4 | calm |
| 19 | 4 | calm |
| 20 | 4 | calm |
| 21 | 4 | calm |
| 22 | 4 | calm |
| 23 | 4 | calm |
| 24 | 4 | calm |
| 25 | 4 | calm |
| 26 | 4 | calm |
| 27 | 4 | calm |
| 28 | 4 | calm |
| 29 | 4 | calm |
| 30 | 4 | calm |
| 31 | 4 | calm |
Sunrise & sunset in December
Daylight runs from about 9 h 24 min at the start of December to 9 h 18 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 6 minutes over December. Sunrise moves from 7:19 AM to 7:38 AM, and sunset from 4:46 PM to 4:54 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 9.4 | 9.4 | 9.4 | 9.4 | 9.4 | 9.4 | 9.4 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.2 | 9.2 | 9.2 | 9.2 | 9.2 | 9.2 | 9.2 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 | 9.3 |
| Sunrise (AM) | 7:19 | 7:20 | 7:21 | 7:22 | 7:23 | 7:24 | 7:24 | 7:25 | 7:26 | 7:27 | 7:28 | 7:28 | 7:29 | 7:30 | 7:31 | 7:31 | 7:32 | 7:32 | 7:33 | 7:33 | 7:34 | 7:34 | 7:35 | 7:35 | 7:36 | 7:36 | 7:36 | 7:37 | 7:37 | 7:37 | 7:38 |
| Sunset (PM) | 4:46 | 4:46 | 4:46 | 4:46 | 4:46 | 4:46 | 4:45 | 4:46 | 4:46 | 4:46 | 4:46 | 4:46 | 4:46 | 4:46 | 4:47 | 4:47 | 4:47 | 4:47 | 4:48 | 4:48 | 4:49 | 4:49 | 4:50 | 4:50 | 4:51 | 4:51 | 4:52 | 4:52 | 4:53 | 4:54 | 4:54 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 9.4 | 7:19 | 4:46 |
| 2 | 9.4 | 7:20 | 4:46 |
| 3 | 9.4 | 7:21 | 4:46 |
| 4 | 9.4 | 7:22 | 4:46 |
| 5 | 9.4 | 7:23 | 4:46 |
| 6 | 9.4 | 7:24 | 4:46 |
| 7 | 9.4 | 7:24 | 4:45 |
| 8 | 9.3 | 7:25 | 4:46 |
| 9 | 9.3 | 7:26 | 4:46 |
| 10 | 9.3 | 7:27 | 4:46 |
| 11 | 9.3 | 7:28 | 4:46 |
| 12 | 9.3 | 7:28 | 4:46 |
| 13 | 9.3 | 7:29 | 4:46 |
| 14 | 9.3 | 7:30 | 4:46 |
| 15 | 9.3 | 7:31 | 4:47 |
| 16 | 9.3 | 7:31 | 4:47 |
| 17 | 9.3 | 7:32 | 4:47 |
| 18 | 9.3 | 7:32 | 4:47 |
| 19 | 9.2 | 7:33 | 4:48 |
| 20 | 9.2 | 7:33 | 4:48 |
| 21 | 9.2 | 7:34 | 4:49 |
| 22 | 9.2 | 7:34 | 4:49 |
| 23 | 9.2 | 7:35 | 4:50 |
| 24 | 9.2 | 7:35 | 4:50 |
| 25 | 9.2 | 7:36 | 4:51 |
| 26 | 9.3 | 7:36 | 4:51 |
| 27 | 9.3 | 7:36 | 4:52 |
| 28 | 9.3 | 7:37 | 4:52 |
| 29 | 9.3 | 7:37 | 4:53 |
| 30 | 9.3 | 7:37 | 4:54 |
| 31 | 9.3 | 7:38 | 4:54 |
Solar energy in December
Average shortwave solar energy reaching the ground each day in December, about 1.92 kWh/m² — the year's lowest.
For context, solar energy here swings from a low near 1.92 kWh/m² to a high of 8.22 kWh/m² in July across the year — December's 1.92 kWh/m² sits near the bottom.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 2.1 | 2.0 | 2.0 | 2.0 | 2.0 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 1.9 | 2.0 |
| Level | Moderate | Moderate | Moderate | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim | Dim |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 2.1 | Moderate |
| 2 | 2.0 | Moderate |
| 3 | 2.0 | Moderate |
| 4 | 2.0 | Dim |
| 5 | 2.0 | Dim |
| 6 | 1.9 | Dim |
| 7 | 1.9 | Dim |
| 8 | 1.9 | Dim |
| 9 | 1.9 | Dim |
| 10 | 1.9 | Dim |
| 11 | 1.9 | Dim |
| 12 | 1.9 | Dim |
| 13 | 1.9 | Dim |
| 14 | 1.9 | Dim |
| 15 | 1.9 | Dim |
| 16 | 1.9 | Dim |
| 17 | 1.9 | Dim |
| 18 | 1.9 | Dim |
| 19 | 1.9 | Dim |
| 20 | 1.9 | Dim |
| 21 | 1.9 | Dim |
| 22 | 1.9 | Dim |
| 23 | 1.9 | Dim |
| 24 | 1.9 | Dim |
| 25 | 1.9 | Dim |
| 26 | 1.9 | Dim |
| 27 | 1.9 | Dim |
| 28 | 1.9 | Dim |
| 29 | 1.9 | Dim |
| 30 | 1.9 | Dim |
| 31 | 2.0 | Dim |
Hazard calendar for Ukiah
In December, Ukiah sits inside its rainy season season. The full year is below, with each hazard's peak months called out.
Ukiah's rainy season runs November–March, when most of the year's rain falls.
Is December a good time to visit Ukiah?
Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
December is a weaker month for outdoor sightseeing in Ukiah.
What to pack for Ukiah in December
From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In December, Ukiah sees daytime highs around 53°F and nights near 36°F. Pack a warm layer. Worth having: rain gear. About 12 days see rain.
Sea temperature near Ukiah in December
The nearest coast averages about 54°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 29 mi away) is warmest in September at about 55°F and coldest in April near 52°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 | 53 | 52 | 52 | 52 | 53 | 54 | 55 | 55 | 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 | 53 | Bracing |
| Apr | 52 | Bracing |
| May | 52 | Bracing |
| Jun | 52 | Bracing |
| Jul | 53 | Bracing |
| Aug | 54 | Bracing |
| Sep | 55 | Bracing |
| Oct | 55 | Bracing |
| Nov | 55 | Bracing |
| Dec | 54 | Bracing |
UV index in Ukiah in December
Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Ukiah peaks around July 10 at about 10 (extreme) — 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 9 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 | 10 | 9 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Extreme | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 9 | Very high |
| Jun | 10 | Very high |
| Jul | 10 | Extreme |
| Aug | 9 | Very high |
| Sep | 6 | High |
| Oct | 5 | Moderate |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Ukiah in December
Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.
Air quality in Ukiah is worst in September — around 31 µg/m³ PM2.5 (moderate), about 5.8× the cleanest month (June, 5 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 | 8 | 9 | 8 | 6 | 5 | 14 | 29 | 31 | 14 | 8 | 6 |
| Level | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 6 | Good |
| Feb | 8 | Good |
| Mar | 9 | Good |
| Apr | 8 | Good |
| May | 6 | Good |
| Jun | 5 | Good |
| Jul | 14 | Moderate |
| Aug | 29 | Moderate |
| Sep | 31 | Moderate |
| Oct | 14 | Moderate |
| Nov | 8 | Good |
| Dec | 6 | Good |
Where is Ukiah?
Ukiah sits at 39.2°N, 123.2°W, 633 ft above sea level, in United States. The nearest listed city is Clearlake, 34 mi away.
Topography around Ukiah
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Ukiah.
Within 2 miles, the terrain around Ukiah has significant variations in elevation — a maximum elevation change of 1,765 ft around an average of 827 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,415 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,362 ft.
The land around Ukiah is covered by trees (51%), artificial surfaces (25%) and grassland (20%) within 2 miles, trees (72%) and grassland (24%) within 10 miles, and trees (59%) 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 Ukiah (39.1502°, -123.2078°, elevation 633 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).