Casa de Oro-Mount Helix weather in December
In December, Casa de Oro-Mount Helix sees average daytime highs of 64°F and overnight lows near 48°F, with 1.9 in of rain across 5.2 wet days and about 9.9 hours of daylight. It is the 11th-warmest and 4th-wettest month of the year here.
Day-to-day highs hold fairly steady near 64°F through the month. The sky is clear or mostly clear about 53% of the time in December, and the air most often feels dry.
Daylight stretches from about 10 hours at the start of December to 9 h 54 min by month's end. Set against the rest of the year, December is Casa de Oro-Mount Helix's 9th-clearest and 5th-windiest month. For the whole year in context, see Casa de Oro-Mount Helix's year-round climate.
- Daytime high
- 64°
- 11th warmest
- Overnight low
- 48°
- 2nd coldest
- Rainfall
- 1.9 in
- 5.2 wet days
- Daylight
- 9 h 54 min
- 6:48 AM – 4:40 PM
- Cloud cover
- 41%
- 9th clearest
- Wind
- 5 mph
- 5th windiest
- Solar energy
- 3.14 kWh/m²
- Travel score
- 6.8
- out of 10
Casa de Oro-Mount Helix is census designated place in San Diego County, California, United States.
- Density
- 1,058/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in December
Day-to-day highs hold fairly steady near 64°F through the month.
A typical December day in Casa de Oro-Mount Helix reaches about 64°F in the afternoon and slips back to 48°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 57°F and 72°F. Set against its neighbours, December runs about 6°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) | 66 | 66 | 66 | 65 | 65 | 65 | 65 | 65 | 65 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 64 |
| Avg low (°F) | 50 | 49 | 49 | 49 | 49 | 49 | 49 | 49 | 48 | 48 | 48 | 48 | 48 | 48 | 48 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 47 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 66 | 50 |
| 2 | 66 | 49 |
| 3 | 66 | 49 |
| 4 | 65 | 49 |
| 5 | 65 | 49 |
| 6 | 65 | 49 |
| 7 | 65 | 49 |
| 8 | 65 | 49 |
| 9 | 65 | 48 |
| 10 | 64 | 48 |
| 11 | 64 | 48 |
| 12 | 64 | 48 |
| 13 | 64 | 48 |
| 14 | 64 | 48 |
| 15 | 64 | 48 |
| 16 | 64 | 47 |
| 17 | 64 | 47 |
| 18 | 64 | 47 |
| 19 | 64 | 47 |
| 20 | 64 | 47 |
| 21 | 63 | 47 |
| 22 | 63 | 47 |
| 23 | 63 | 47 |
| 24 | 63 | 47 |
| 25 | 63 | 47 |
| 26 | 63 | 47 |
| 27 | 63 | 47 |
| 28 | 63 | 47 |
| 29 | 63 | 47 |
| 30 | 63 | 47 |
| 31 | 64 | 47 |
Casa de Oro-Mount Helix weather by month
How December compares with the rest of the year at a glance. December is the 11th-warmest and 4th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 64° / 48° | 2.3 | 5.6 | 10.1 | 6.8 |
| Feb | 64° / 48° | 2.9 | 7 | 10.8 | 6.3 |
| Mar | 65° / 50° | 1.9 | 5.8 | 11.8 | 6.8 |
| Apr | 68° / 53° | 0.9 | 3.9 | 12.8 | 7.6 |
| May | 70° / 56° | 0.4 | 2 | 13.7 | 8.2 |
| Jun | 74° / 60° | 0.1 | 0.6 | 14.1 | 9.2 |
| Jul | 79° / 64° | 0.1 | 0.7 | 13.9 | 8.9 |
| Aug | 81° / 65° | 0.1 | 0.5 | 13.2 | 8.7 |
| Sep | 80° / 64° | 0.2 | 0.9 | 12.2 | 8.8 |
| Oct | 76° / 59° | 0.6 | 2.5 | 11.2 | 8.7 |
| Nov | 70° / 53° | 0.9 | 3.3 | 10.3 | 7.9 |
| Dec | 64° / 48° | 1.9 | 5.2 | 9.9 | 6.8 |
Cloud cover in December
The sky is clear or mostly clear about 53% of the time in December.
Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 36%.
| 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 (%) | 67 | 66 | 65 | 65 | 65 | 65 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 65 | 65 | 65 | 65 | 65 | 64 | 64 | 64 | 65 | 65 | 64 | 64 | 63 | 63 | 63 | 62 | 62 | 62 |
| Cloudier (%) | 33 | 34 | 35 | 35 | 35 | 35 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 35 | 35 | 35 | 35 | 35 | 36 | 36 | 36 | 35 | 35 | 36 | 36 | 37 | 37 | 37 | 38 | 38 | 38 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 67 | 33 |
| 2 | 66 | 34 |
| 3 | 65 | 35 |
| 4 | 65 | 35 |
| 5 | 65 | 35 |
| 6 | 65 | 35 |
| 7 | 64 | 36 |
| 8 | 64 | 36 |
| 9 | 64 | 36 |
| 10 | 64 | 36 |
| 11 | 64 | 36 |
| 12 | 64 | 36 |
| 13 | 64 | 36 |
| 14 | 65 | 35 |
| 15 | 65 | 35 |
| 16 | 65 | 35 |
| 17 | 65 | 35 |
| 18 | 65 | 35 |
| 19 | 64 | 36 |
| 20 | 64 | 36 |
| 21 | 64 | 36 |
| 22 | 65 | 35 |
| 23 | 65 | 35 |
| 24 | 64 | 36 |
| 25 | 64 | 36 |
| 26 | 63 | 37 |
| 27 | 63 | 37 |
| 28 | 63 | 37 |
| 29 | 62 | 38 |
| 30 | 62 | 38 |
| 31 | 62 | 38 |
Chance of precipitation in December
Casa de Oro-Mount Helix gets around 1.9 in of rain over 5.2 wet days in December. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 17% and peaks near 18% on the wettest days.
| 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 (%) | 15 | 15 | 16 | 16 | 16 | 16 | 16 | 17 | 17 | 17 | 17 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 17 | 17 | 17 | 17 | 17 | 18 | 18 | 18 |
| Rain chance (%) | |
|---|---|
| 1 | 15 |
| 2 | 15 |
| 3 | 16 |
| 4 | 16 |
| 5 | 16 |
| 6 | 16 |
| 7 | 16 |
| 8 | 17 |
| 9 | 17 |
| 10 | 17 |
| 11 | 17 |
| 12 | 18 |
| 13 | 18 |
| 14 | 18 |
| 15 | 18 |
| 16 | 18 |
| 17 | 18 |
| 18 | 18 |
| 19 | 18 |
| 20 | 18 |
| 21 | 18 |
| 22 | 18 |
| 23 | 18 |
| 24 | 17 |
| 25 | 17 |
| 26 | 17 |
| 27 | 17 |
| 28 | 17 |
| 29 | 18 |
| 30 | 18 |
| 31 | 18 |
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 98% 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 (%) | 97 | 97 | 97 | 97 | 97 | 97 | 97 | 97 | 98 | 98 | 98 | 98 | 98 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 | 99 |
| Comfortable (%) | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Dry (%) | Comfortable (%) | |
|---|---|---|
| 1 | 97 | 3 |
| 2 | 97 | 3 |
| 3 | 97 | 3 |
| 4 | 97 | 3 |
| 5 | 97 | 3 |
| 6 | 97 | 3 |
| 7 | 97 | 3 |
| 8 | 97 | 3 |
| 9 | 98 | 2 |
| 10 | 98 | 2 |
| 11 | 98 | 2 |
| 12 | 98 | 2 |
| 13 | 98 | 2 |
| 14 | 99 | 1 |
| 15 | 99 | 1 |
| 16 | 99 | 1 |
| 17 | 99 | 1 |
| 18 | 99 | 1 |
| 19 | 99 | 1 |
| 20 | 99 | 1 |
| 21 | 99 | 1 |
| 22 | 99 | 1 |
| 23 | 99 | 1 |
| 24 | 99 | 1 |
| 25 | 99 | 1 |
| 26 | 99 | 1 |
| 27 | 99 | 1 |
| 28 | 99 | 1 |
| 29 | 99 | 1 |
| 30 | 99 | 1 |
| 31 | 99 | 1 |
Wind in December
Winds average 5 mph in December.
Across December, daily wind ranges from about 5 mph on the calmest days to 5 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) | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
| 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 | 5 | calm |
| 2 | 5 | calm |
| 3 | 5 | calm |
| 4 | 5 | calm |
| 5 | 5 | calm |
| 6 | 5 | calm |
| 7 | 5 | calm |
| 8 | 5 | calm |
| 9 | 5 | calm |
| 10 | 5 | calm |
| 11 | 5 | calm |
| 12 | 5 | calm |
| 13 | 5 | calm |
| 14 | 5 | calm |
| 15 | 5 | calm |
| 16 | 5 | calm |
| 17 | 5 | calm |
| 18 | 5 | calm |
| 19 | 5 | calm |
| 20 | 5 | calm |
| 21 | 5 | calm |
| 22 | 5 | calm |
| 23 | 5 | calm |
| 24 | 5 | calm |
| 25 | 5 | calm |
| 26 | 5 | calm |
| 27 | 5 | calm |
| 28 | 5 | calm |
| 29 | 5 | calm |
| 30 | 5 | calm |
| 31 | 5 | calm |
Sunrise & sunset in December
Daylight runs from about 10 hours at the start of December to 9 h 54 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 6:38 AM to 6:55 AM, and sunset from 4:38 PM to 4:47 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) | 10.0 | 10.0 | 10.0 | 10.0 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.9 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.8 | 9.9 | 9.9 | 9.9 | 9.9 |
| Sunrise (AM) | 6:38 | 6:38 | 6:39 | 6:40 | 6:41 | 6:42 | 6:42 | 6:43 | 6:44 | 6:45 | 6:45 | 6:46 | 6:47 | 6:47 | 6:48 | 6:48 | 6:49 | 6:50 | 6:50 | 6:51 | 6:51 | 6:52 | 6:52 | 6:53 | 6:53 | 6:53 | 6:54 | 6:54 | 6:54 | 6:55 | 6:55 |
| Sunset (PM) | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:38 | 4:39 | 4:39 | 4:39 | 4:39 | 4:40 | 4:40 | 4:40 | 4:41 | 4:41 | 4:42 | 4:42 | 4:43 | 4:43 | 4:44 | 4:44 | 4:45 | 4:45 | 4:46 | 4:46 | 4:47 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 10.0 | 6:38 | 4:38 |
| 2 | 10.0 | 6:38 | 4:38 |
| 3 | 10.0 | 6:39 | 4:38 |
| 4 | 10.0 | 6:40 | 4:38 |
| 5 | 9.9 | 6:41 | 4:38 |
| 6 | 9.9 | 6:42 | 4:38 |
| 7 | 9.9 | 6:42 | 4:38 |
| 8 | 9.9 | 6:43 | 4:38 |
| 9 | 9.9 | 6:44 | 4:38 |
| 10 | 9.9 | 6:45 | 4:38 |
| 11 | 9.9 | 6:45 | 4:38 |
| 12 | 9.9 | 6:46 | 4:39 |
| 13 | 9.9 | 6:47 | 4:39 |
| 14 | 9.9 | 6:47 | 4:39 |
| 15 | 9.9 | 6:48 | 4:39 |
| 16 | 9.9 | 6:48 | 4:40 |
| 17 | 9.8 | 6:49 | 4:40 |
| 18 | 9.8 | 6:50 | 4:40 |
| 19 | 9.8 | 6:50 | 4:41 |
| 20 | 9.8 | 6:51 | 4:41 |
| 21 | 9.8 | 6:51 | 4:42 |
| 22 | 9.8 | 6:52 | 4:42 |
| 23 | 9.8 | 6:52 | 4:43 |
| 24 | 9.8 | 6:53 | 4:43 |
| 25 | 9.8 | 6:53 | 4:44 |
| 26 | 9.8 | 6:53 | 4:44 |
| 27 | 9.8 | 6:54 | 4:45 |
| 28 | 9.9 | 6:54 | 4:45 |
| 29 | 9.9 | 6:54 | 4:46 |
| 30 | 9.9 | 6:55 | 4:46 |
| 31 | 9.9 | 6:55 | 4:47 |
Solar energy in December
Average shortwave solar energy reaching the ground each day in December, about 3.14 kWh/m² — the year's lowest.
For context, solar energy here swings from a low near 3.14 kWh/m² to a high of 8.08 kWh/m² in June across the year — December's 3.14 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) | 3.3 | 3.2 | 3.2 | 3.2 | 3.2 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.1 | 3.2 | 3.2 | 3.2 | 3.2 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 3.3 | Moderate |
| 2 | 3.2 | Moderate |
| 3 | 3.2 | Moderate |
| 4 | 3.2 | Moderate |
| 5 | 3.2 | Moderate |
| 6 | 3.1 | Moderate |
| 7 | 3.1 | Moderate |
| 8 | 3.1 | Moderate |
| 9 | 3.1 | Moderate |
| 10 | 3.1 | Moderate |
| 11 | 3.1 | Moderate |
| 12 | 3.1 | Moderate |
| 13 | 3.1 | Moderate |
| 14 | 3.0 | Moderate |
| 15 | 3.0 | Moderate |
| 16 | 3.0 | Moderate |
| 17 | 3.0 | Moderate |
| 18 | 3.0 | Moderate |
| 19 | 3.1 | Moderate |
| 20 | 3.1 | Moderate |
| 21 | 3.1 | Moderate |
| 22 | 3.1 | Moderate |
| 23 | 3.1 | Moderate |
| 24 | 3.1 | Moderate |
| 25 | 3.1 | Moderate |
| 26 | 3.1 | Moderate |
| 27 | 3.1 | Moderate |
| 28 | 3.2 | Moderate |
| 29 | 3.2 | Moderate |
| 30 | 3.2 | Moderate |
| 31 | 3.2 | Moderate |
Is December a good time to visit Casa de Oro-Mount Helix?
Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
December is a reasonable time to visit Casa de Oro-Mount Helix for sightseeing.
What to pack for Casa de Oro-Mount Helix in December
From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In December, Casa de Oro-Mount Helix sees daytime highs around 64°F and nights near 48°F. Little to plan around — just the basics. About 5 days see rain.
Sea temperature near Casa de Oro-Mount Helix in December
The nearest coast averages about 61°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 13 mi away) is warmest in August at about 70°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) | 60 | 59 | 60 | 61 | 63 | 65 | 68 | 70 | 69 | 67 | 64 | 61 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing | Refreshing | Cool | Cool | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 60 | Cool |
| Feb | 59 | Cool |
| Mar | 60 | Cool |
| Apr | 61 | Cool |
| May | 63 | Cool |
| Jun | 65 | Cool |
| Jul | 68 | Refreshing |
| Aug | 70 | Refreshing |
| Sep | 69 | Refreshing |
| Oct | 67 | Cool |
| Nov | 64 | Cool |
| Dec | 61 | Cool |
UV index in Casa de Oro-Mount Helix in December
Clear-sky midday UV in December peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Casa de Oro-Mount Helix peaks around June 22 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month 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 | 11 | 9 | 6 | 4 | 3 |
| Level | Moderate | Moderate | High | Very high | Very high | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 5 | Moderate |
| Mar | 5 | High |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Air quality in Casa de Oro-Mount Helix 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 Casa de Oro-Mount Helix is worst in September — around 26 µg/m³ PM2.5 (moderate), about 3.4× the cleanest month (May, 8 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) | 12 | 12 | 12 | 11 | 8 | 11 | 11 | 15 | 26 | 14 | 12 | 16 |
| Level | Good | Moderate | Moderate | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 12 | Good |
| Feb | 12 | Moderate |
| Mar | 12 | Moderate |
| Apr | 11 | Good |
| May | 8 | Good |
| Jun | 11 | Good |
| Jul | 11 | Good |
| Aug | 15 | Moderate |
| Sep | 26 | Moderate |
| Oct | 14 | Moderate |
| Nov | 12 | Moderate |
| Dec | 16 | Moderate |
Where is Casa de Oro-Mount Helix?
Casa de Oro-Mount Helix sits at 32.8°N, 117.0°W, 840 ft above sea level, in United States. The nearest listed city is El Cajon, 1.9 mi away.
Topography around Casa de Oro-Mount Helix
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Casa de Oro-Mount Helix.
Within 2 miles, the terrain around Casa de Oro-Mount Helix has significant variations in elevation — a maximum elevation change of 932 ft around an average of 643 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,762 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,430 ft.
The land around Casa de Oro-Mount Helix is covered by artificial surfaces (59%) and trees (31%) within 2 miles, artificial surfaces (40%) and shrubs (26%) within 10 miles, and shrubs (27%) and water (27%) 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 Casa de Oro-Mount Helix (32.764°, -116.9688°, elevation 840 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).