Alum Rock weather in April
In April, Alum Rock sees average daytime highs of 65°F and overnight lows near 45°F, with 1.6 in of rain across 5.7 wet days and about 12.9 hours of daylight. It is the 7th-warmest and 6th-wettest month of the year here.
Highs climb over the month, from about 63°F in the first days to 68°F by the end. The sky is clear or mostly clear about 45% of the time in April, and the air most often feels dry.
Daylight stretches from about 12 h 24 min at the start of April to 13 h 30 min by month's end. Set against the rest of the year, April is Alum Rock's 8th-clearest and 1st-windiest month. For the whole year in context, see Alum Rock's year-round climate.
- Daytime high
- 65°
- 7th warmest
- Overnight low
- 45°
- 6th coldest
- Rainfall
- 1.6 in
- 5.7 wet days
- Daylight
- 13 hours
- 5:39 AM – 6:36 PM
- Cloud cover
- 46%
- 8th clearest
- Wind
- 5 mph
- 1st windiest
- Solar energy
- 6.22 kWh/m²
- Travel score
- 6.7
- out of 10
Alum Rock is census-designated place in Santa Clara County, California.
- Density
- 7,068/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in April
Highs climb over the month, from about 63°F in the first days to 68°F by the end.
A typical April day in Alum Rock reaches about 65°F in the afternoon and slips back to 45°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 55°F and 76°F. Set against its neighbours, April runs about 4°F warmer than March and about 6°F cooler than May.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 63 | 64 | 64 | 64 | 64 | 64 | 65 | 65 | 65 | 65 | 66 | 66 | 66 | 67 | 67 | 67 | 67 | 68 | 68 | 68 | 69 | 69 |
| Avg low (°F) | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 44 | 45 | 45 | 45 | 45 | 45 | 45 | 46 | 46 | 46 | 46 | 46 | 46 | 46 | 47 | 47 | 47 | 47 | 47 | 47 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 63 | 44 |
| 2 | 63 | 44 |
| 3 | 63 | 44 |
| 4 | 63 | 44 |
| 5 | 63 | 44 |
| 6 | 63 | 44 |
| 7 | 63 | 44 |
| 8 | 63 | 44 |
| 9 | 63 | 44 |
| 10 | 64 | 44 |
| 11 | 64 | 44 |
| 12 | 64 | 45 |
| 13 | 64 | 45 |
| 14 | 64 | 45 |
| 15 | 65 | 45 |
| 16 | 65 | 45 |
| 17 | 65 | 45 |
| 18 | 65 | 46 |
| 19 | 66 | 46 |
| 20 | 66 | 46 |
| 21 | 66 | 46 |
| 22 | 67 | 46 |
| 23 | 67 | 46 |
| 24 | 67 | 46 |
| 25 | 67 | 47 |
| 26 | 68 | 47 |
| 27 | 68 | 47 |
| 28 | 68 | 47 |
| 29 | 69 | 47 |
| 30 | 69 | 47 |
Alum Rock weather by month
How April compares with the rest of the year at a glance. April is the 7th-warmest and 6th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 56° / 40° | 4.4 | 9.1 | 9.7 | 4.1 |
| Feb | 58° / 42° | 4.4 | 9.2 | 10.6 | 4.4 |
| Mar | 61° / 44° | 3.3 | 9.2 | 11.7 | 5.4 |
| Apr | 65° / 45° | 1.6 | 5.7 | 12.9 | 6.7 |
| May | 71° / 49° | 0.8 | 3.4 | 14 | 8.1 |
| Jun | 77° / 53° | 0.2 | 0.8 | 14.5 | 9.1 |
| Jul | 82° / 57° | 0.1 | 0.2 | 14.3 | 8.8 |
| Aug | 82° / 57° | 0.0 | 0.3 | 13.4 | 8.8 |
| Sep | 80° / 56° | 0.1 | 0.6 | 12.3 | 8.9 |
| Oct | 73° / 51° | 1.0 | 2.8 | 11 | 8.6 |
| Nov | 63° / 44° | 1.9 | 5.7 | 10 | 6.2 |
| Dec | 56° / 40° | 3.9 | 8.8 | 9.5 | 4.0 |
Cloud cover in April
The sky is clear or mostly clear about 45% of the time in April.
Beyond those clear spells, partly cloudy skies cover about 15% of April, with mostly cloudy or overcast conditions the remaining 40%. Skies tend to open up as the month goes on.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 55 | 55 | 56 | 56 | 57 | 57 | 58 | 60 | 60 | 61 | 62 | 63 | 63 | 65 | 65 | 66 | 66 | 66 | 67 | 67 | 67 | 68 |
| Cloudier (%) | 46 | 46 | 46 | 46 | 46 | 46 | 46 | 46 | 45 | 45 | 44 | 44 | 43 | 43 | 42 | 40 | 40 | 39 | 38 | 37 | 37 | 35 | 35 | 34 | 34 | 34 | 33 | 33 | 33 | 32 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 54 | 46 |
| 2 | 54 | 46 |
| 3 | 54 | 46 |
| 4 | 54 | 46 |
| 5 | 54 | 46 |
| 6 | 54 | 46 |
| 7 | 54 | 46 |
| 8 | 54 | 46 |
| 9 | 55 | 45 |
| 10 | 55 | 45 |
| 11 | 56 | 44 |
| 12 | 56 | 44 |
| 13 | 57 | 43 |
| 14 | 57 | 43 |
| 15 | 58 | 42 |
| 16 | 60 | 40 |
| 17 | 60 | 40 |
| 18 | 61 | 39 |
| 19 | 62 | 38 |
| 20 | 63 | 37 |
| 21 | 63 | 37 |
| 22 | 65 | 35 |
| 23 | 65 | 35 |
| 24 | 66 | 34 |
| 25 | 66 | 34 |
| 26 | 66 | 34 |
| 27 | 67 | 33 |
| 28 | 67 | 33 |
| 29 | 67 | 33 |
| 30 | 68 | 32 |
Chance of precipitation in April
Alum Rock gets around 1.6 in of rain over 5.7 wet days in April. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 20% and peaks near 24% on the wettest days. The odds ease toward the end of the month.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 24 | 24 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 22 | 22 | 21 | 20 | 20 | 19 | 18 | 17 | 17 | 16 | 16 | 15 | 15 | 15 | 14 | 14 | 14 | 13 |
| Rain chance (%) | |
|---|---|
| 1 | 24 |
| 2 | 24 |
| 3 | 23 |
| 4 | 23 |
| 5 | 23 |
| 6 | 23 |
| 7 | 23 |
| 8 | 23 |
| 9 | 23 |
| 10 | 23 |
| 11 | 23 |
| 12 | 23 |
| 13 | 22 |
| 14 | 22 |
| 15 | 21 |
| 16 | 20 |
| 17 | 20 |
| 18 | 19 |
| 19 | 18 |
| 20 | 17 |
| 21 | 17 |
| 22 | 16 |
| 23 | 16 |
| 24 | 15 |
| 25 | 15 |
| 26 | 15 |
| 27 | 14 |
| 28 | 14 |
| 29 | 14 |
| 30 | 13 |
Humidity in April
Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, April 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | 99 | 99 | 99 | 99 |
| Comfortable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
| Dry (%) | Comfortable (%) | |
|---|---|---|
| 1 | 100 | 0 |
| 2 | 100 | 0 |
| 3 | 100 | 0 |
| 4 | 100 | 0 |
| 5 | 100 | 0 |
| 6 | 100 | 0 |
| 7 | 100 | 0 |
| 8 | 100 | 0 |
| 9 | 100 | 0 |
| 10 | 100 | 0 |
| 11 | 100 | 0 |
| 12 | 100 | 0 |
| 13 | 100 | 0 |
| 14 | 100 | 0 |
| 15 | 100 | 0 |
| 16 | 100 | 0 |
| 17 | 100 | 0 |
| 18 | 100 | 0 |
| 19 | 100 | 0 |
| 20 | 100 | 0 |
| 21 | 100 | 0 |
| 22 | 100 | 0 |
| 23 | 100 | 0 |
| 24 | 100 | 0 |
| 25 | 100 | 0 |
| 26 | 100 | 0 |
| 27 | 99 | 1 |
| 28 | 99 | 1 |
| 29 | 99 | 1 |
| 30 | 99 | 1 |
Wind in April
Winds average 5 mph in April, the windiest month of the year.
Across April, 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| 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 |
| 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 |
Sunrise & sunset in April
Daylight runs from about 12 h 24 min at the start of April to 13 h 30 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 66 minutes over April. Sunrise moves from 6:01 AM to 5:20 AM, and sunset from 6:23 PM to 6:49 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.4 | 12.4 | 12.4 | 12.5 | 12.5 | 12.6 | 12.6 | 12.6 | 12.7 | 12.7 | 12.8 | 12.8 | 12.8 | 12.9 | 12.9 | 13.0 | 13.0 | 13.0 | 13.1 | 13.1 | 13.2 | 13.2 | 13.2 | 13.3 | 13.3 | 13.3 | 13.4 | 13.4 | 13.4 | 13.5 |
| Sunrise (AM) | 6:01 | 6:00 | 5:58 | 5:57 | 5:55 | 5:54 | 5:52 | 5:51 | 5:49 | 5:48 | 5:46 | 5:45 | 5:43 | 5:42 | 5:40 | 5:39 | 5:37 | 5:36 | 5:35 | 5:33 | 5:32 | 5:30 | 5:29 | 5:28 | 5:26 | 5:25 | 5:24 | 5:23 | 5:21 | 5:20 |
| Sunset (PM) | 6:23 | 6:24 | 6:25 | 6:25 | 6:26 | 6:27 | 6:28 | 6:29 | 6:30 | 6:31 | 6:32 | 6:33 | 6:34 | 6:35 | 6:35 | 6:36 | 6:37 | 6:38 | 6:39 | 6:40 | 6:41 | 6:42 | 6:43 | 6:44 | 6:45 | 6:45 | 6:46 | 6:47 | 6:48 | 6:49 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.4 | 6:01 | 6:23 |
| 2 | 12.4 | 6:00 | 6:24 |
| 3 | 12.4 | 5:58 | 6:25 |
| 4 | 12.5 | 5:57 | 6:25 |
| 5 | 12.5 | 5:55 | 6:26 |
| 6 | 12.6 | 5:54 | 6:27 |
| 7 | 12.6 | 5:52 | 6:28 |
| 8 | 12.6 | 5:51 | 6:29 |
| 9 | 12.7 | 5:49 | 6:30 |
| 10 | 12.7 | 5:48 | 6:31 |
| 11 | 12.8 | 5:46 | 6:32 |
| 12 | 12.8 | 5:45 | 6:33 |
| 13 | 12.8 | 5:43 | 6:34 |
| 14 | 12.9 | 5:42 | 6:35 |
| 15 | 12.9 | 5:40 | 6:35 |
| 16 | 13.0 | 5:39 | 6:36 |
| 17 | 13.0 | 5:37 | 6:37 |
| 18 | 13.0 | 5:36 | 6:38 |
| 19 | 13.1 | 5:35 | 6:39 |
| 20 | 13.1 | 5:33 | 6:40 |
| 21 | 13.2 | 5:32 | 6:41 |
| 22 | 13.2 | 5:30 | 6:42 |
| 23 | 13.2 | 5:29 | 6:43 |
| 24 | 13.3 | 5:28 | 6:44 |
| 25 | 13.3 | 5:26 | 6:45 |
| 26 | 13.3 | 5:25 | 6:45 |
| 27 | 13.4 | 5:24 | 6:46 |
| 28 | 13.4 | 5:23 | 6:47 |
| 29 | 13.4 | 5:21 | 6:48 |
| 30 | 13.5 | 5:20 | 6:49 |
Solar energy in April
Average shortwave solar energy reaching the ground each day in April, about 6.22 kWh/m².
For context, solar energy here swings from a low near 2.36 kWh/m² to a high of 7.99 kWh/m² in June across the year — April's 6.22 kWh/m² falls in the middle.
| 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.6 | 5.6 | 5.7 | 5.7 | 5.7 | 5.8 | 5.8 | 5.9 | 5.9 | 6.0 | 6.0 | 6.0 | 6.1 | 6.1 | 6.2 | 6.2 | 6.3 | 6.3 | 6.4 | 6.4 | 6.5 | 6.5 | 6.5 | 6.6 | 6.6 | 6.7 | 6.7 | 6.8 | 6.8 | 6.8 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.6 | Bright |
| 2 | 5.6 | Bright |
| 3 | 5.7 | Bright |
| 4 | 5.7 | Bright |
| 5 | 5.7 | Bright |
| 6 | 5.8 | Bright |
| 7 | 5.8 | Bright |
| 8 | 5.9 | Bright |
| 9 | 5.9 | Bright |
| 10 | 6.0 | Bright |
| 11 | 6.0 | Intense |
| 12 | 6.0 | Intense |
| 13 | 6.1 | Intense |
| 14 | 6.1 | Intense |
| 15 | 6.2 | Intense |
| 16 | 6.2 | Intense |
| 17 | 6.3 | Intense |
| 18 | 6.3 | Intense |
| 19 | 6.4 | Intense |
| 20 | 6.4 | Intense |
| 21 | 6.5 | Intense |
| 22 | 6.5 | Intense |
| 23 | 6.5 | Intense |
| 24 | 6.6 | Intense |
| 25 | 6.6 | Intense |
| 26 | 6.7 | Intense |
| 27 | 6.7 | Intense |
| 28 | 6.8 | Intense |
| 29 | 6.8 | Intense |
| 30 | 6.8 | Intense |
Hazard calendar for Alum Rock
None of Alum Rock's seasonal hazards are active in April. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Alum Rock's rainy season runs December–March, when most of the year's rain falls.
Is April a good time to visit Alum Rock?
Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
April is a reasonable time to visit Alum Rock for sightseeing.
What to pack for Alum Rock in April
From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In April, Alum Rock sees daytime highs around 65°F and nights near 45°F. Pack sun protection. Worth having: a warm layer. About 6 days see rain.
Sea temperature near Alum Rock in April
The nearest coast averages about 54°F in April — 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 August at about 59°F and coldest in April near 54°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) | 54 | 54 | 54 | 54 | 54 | 55 | 57 | 59 | 59 | 58 | 56 | 55 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 54 | Bracing |
| Feb | 54 | Bracing |
| Mar | 54 | Bracing |
| Apr | 54 | Bracing |
| May | 54 | Bracing |
| Jun | 55 | Bracing |
| Jul | 57 | Bracing |
| Aug | 59 | Bracing |
| Sep | 59 | Bracing |
| Oct | 58 | Bracing |
| Nov | 56 | Bracing |
| Dec | 55 | Bracing |
UV index in Alum Rock in April
Clear-sky midday UV in April peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Alum Rock peaks around June 23 at about 10 (extreme) — 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) | 3 | 4 | 5 | 7 | 8 | 10 | 10 | 10 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme | Very high | High | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 10 | Very high |
| Sep | 6 | High |
| Oct | 5 | High |
| Nov | 2 | Moderate |
| Dec | 2 | Moderate |
Air quality in Alum Rock in April
Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.
Air quality in Alum Rock is worst in August — around 34 µg/m³ PM2.5 (moderate), about 4.9× 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 | 9 | 34 | 16 | 14 | 15 | 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 | 9 | Good |
| Aug | 34 | Moderate |
| Sep | 16 | Moderate |
| Oct | 14 | Moderate |
| Nov | 15 | Moderate |
| Dec | 12 | Good |
Where is Alum Rock?
Alum Rock sits at 37.4°N, 121.8°W, 151 ft above sea level, in United States. The nearest listed city is San Jose, 4.3 mi away.
Topography around Alum Rock
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Alum Rock.
Within 2 miles, the terrain around Alum Rock has significant variations in elevation — a maximum elevation change of 1,129 ft around an average of 240 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,921 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,373 ft.
The land around Alum Rock is covered by artificial surfaces (73%) within 2 miles, artificial surfaces (42%), grassland (33%) and trees (22%) within 10 miles, and grassland (29%), trees (25%) and water (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 Alum Rock (37.3661°, -121.8272°, elevation 151 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).